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ICC S1 Structural Steel and Bolting study materials
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ICC S1 Structural Steel and Bolting practice questions

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Question 1Code Administration, Plans and Specification Review for Structural Steel

A shop drawing detail for a beam-to-column connection conflicts with the approved, sealed construction documents. Which document governs the work?

  1. The approved construction documents Correct answer.
  2. The fabricator's standard connection detail
  3. The erector's preferred field detail
  4. The most recently dated shop drawing

Explanation

The approved construction documents, including sealed plans and specifications, are the contract documents of record and govern the work. Shop drawings are prepared only to illustrate how the work will be accomplished and must conform to them, so a conflict must be resolved by the design professional before construction proceeds.

Question 2Code Administration, Plans and Specification Review for Structural Steel

Which document identifies the structural steel items that require special inspection and the extent of that inspection?

  1. The statement of special inspections Correct answer.
  2. The fabricator's quality control manual
  3. The erection drawings issued by the erector
  4. The mill test reports for the project steel

Explanation

The registered design professional in responsible charge prepares a statement of special inspections that lists the systems and components requiring special inspection, along with the type and extent of inspection. It is submitted with the permit application and defines the special inspector's scope of work.

Question 3Code Administration, Plans and Specification Review for Structural Steel

The AISC Code of Standard Practice (AISC 303) primarily establishes which of the following?

  1. Welding procedure qualification rules for groove welds
  2. Recognized standards of practice for the responsibilities of the parties Correct answer.
  3. Seismic force-resisting system detailing requirements
  4. Bolt tension calibration frequencies for pretensioned joints

Explanation

AISC 303 describes the recognized customs and usages of the steel construction industry, including the responsibilities of the owner, design professional, fabricator, and erector. Detailed welding qualification rules reside in AWS D1.1 and bolting rules in the RCSC Specification, while seismic detailing is addressed elsewhere.

Question 4Code Administration, Plans and Specification Review for Structural Steel

A mill test report for structural steel primarily documents which of the following?

  1. The heat's chemical analysis and tensile properties Correct answer.
  2. Bolt tension results recorded during shop assembly
  3. Welder qualification records from the producing mill
  4. Shop primer thickness measurements taken before shipment

Explanation

Mill test reports, often called mill certificates, report the chemical composition and mechanical properties such as yield and tensile strength for each heat of steel. The inspector compares them with the specified ASTM designation and grade to confirm material conformance.

Question 5Code Administration, Plans and Specification Review for Structural Steel

Under AWS D1.1, which party is responsible for qualifying a welder?

  1. The welder's employer Correct answer.
  2. The engineer of record
  3. The building official
  4. The special inspector

Explanation

AWS D1.1 places responsibility for welder qualification on the employer, who must keep records showing each welder is qualified for the process, position, and thickness being used. The special inspector verifies that valid qualification records exist but does not qualify the welder.

Question 6Code Administration, Plans and Specification Review for Structural Steel

Structural steel shop drawings are normally prepared by which party?

  1. The owner's testing laboratory
  2. The engineer of record
  3. The fabricator Correct answer.
  4. The erector

Explanation

AISC 303 assigns preparation of shop drawings to the fabricator, who details the individual members and connections to be produced. The engineer of record reviews them for conformance with the design concept but does not prepare them.

Question 7Code Administration, Plans and Specification Review for Structural Steel

Before welding begins, the special inspector should confirm that which of the following is available?

  1. A single WPS covering every joint on the project
  2. A complete set of radiographic films for the first day's production
  3. A current welder's union card for each welder on site
  4. A qualified WPS and welder qualification records for the joints to be welded Correct answer.

Explanation

Welding must follow a WPS that is either prequalified under AWS D1.1 or qualified by testing recorded in a PQR, and each welder must be qualified to that procedure. The inspector confirms that both documents are in place before production welding begins.

Question 8Code Administration, Plans and Specification Review for Structural Steel

For a slip-critical bolted connection, the inspector should verify which of the following?

  1. That bolts are fully galvanized after tightening
  2. That bolts were installed with an impact wrench only
  3. That the faying surfaces meet the specified surface preparation Correct answer.
  4. That each bolt was tensioned twice to the same value

Explanation

Slip-critical joints transfer load through friction between faying surfaces, so the specified surface condition such as clean mill scale, blast cleaning, or an approved coating must be present before assembly. Contaminated or improperly coated faying surfaces that do not match the specified class reduce the slip resistance.

Question 9Code Administration, Plans and Specification Review for Structural Steel

For turn-of-nut installation, what should the inspector primarily verify?

  1. That direct tension indicators show the required gap
  2. That a calibrated torque wrench recorded the final torque
  3. That the specified rotation is confirmed by match marks Correct answer.
  4. That each bolt was tightened twice to the same value

Explanation

Turn-of-nut tightening is controlled by rotating the nut or bolt head a specified amount from the snug-tight condition, and match marks are used to confirm that rotation. If the required rotation is exceeded or the joint is loosened, the fastener must be replaced.

Question 10Code Administration, Plans and Specification Review for Structural Steel

Structural observation differs from special inspection in which of the following ways?

  1. It is performed by the structural engineer for design intent Correct answer.
  2. It replaces the need for all special inspection
  3. It is limited to the welding operations
  4. It is performed only by the building official

Explanation

Structural observation is visual observation by the structural engineer of record or a designated representative to confirm that completed work conforms to the design intent. It supplements, but never replaces, the special inspections listed in the statement of special inspections.

Question 11Code Administration, Plans and Specification Review for Structural Steel

A revised structural drawing is issued during construction. The special inspector should do which of the following?

  1. Continue using the drawings already on the site
  2. Wait for the building official to deliver a copy
  3. Apply the revision only if the fabricator agrees to it
  4. Obtain the current approved revision and log it Correct answer.

Explanation

Inspection must be based on the current approved construction documents, so the inspector obtains the revision through the project document control process and records the governing revision in the inspection records. Work already performed to a superseded drawing must be re-evaluated against the revision.

Question 12Code Administration, Plans and Specification Review for Structural Steel

Where connection design is delegated to the fabricator's engineer, which of the following is required?

  1. The building official designs the connections
  2. The fabricator alone approves the connections as final and complete
  3. The engineer of record reviews and approves the details Correct answer.
  4. The special inspector performs the connection calculations

Explanation

Delegated connection design does not transfer overall design responsibility away from the engineer of record, who must review the submitted details and calculations for conformance with the design concept. Fabrication of those connections should not proceed until the approval is documented.

Question 13Code Administration, Plans and Specification Review for Structural Steel

Per AISC 303, erection drawings show which of the following?

  1. The mill test reports for each heat of steel
  2. The location, orientation, and final position of members Correct answer.
  3. The bolt tension values recorded in the shop
  4. The welding procedures and welder qualification records

Explanation

Erection drawings are prepared by the erector and show the location, orientation, and final position of individual structural members so the structure can be assembled as designed. They are distinct from shop drawings, which detail the fabrication of each piece.

Question 14Code Administration, Plans and Specification Review for Structural Steel

The fabricator proposes to substitute ASTM A36 for the specified ASTM A992 steel. What is required?

  1. A note on the mill test report only
  2. Written approval of the substitution by the engineer of record Correct answer.
  3. Verbal acceptance from the special inspector
  4. Nothing, because both steels have the same yield point

Explanation

A992 and A36 differ in yield strength, chemistry, and weldability, so substituting one for the other is a design change requiring written approval from the engineer of record. The inspector documents the substitution and confirms that substituted material is used only after approval is issued.

Question 15Code Administration, Plans and Specification Review for Structural Steel

A Welding Procedure Qualification Record (PQR) documents which of the following?

  1. The nondestructive testing schedule for the project
  2. The visual inspection results for production welds
  3. The welder's employment history and continuity records
  4. The test results that qualified a welding procedure Correct answer.

Explanation

A PQR records the essential variables used to weld a test coupon along with the mechanical test results, such as tensile and bend tests, that show the procedure produces sound welds. That qualified procedure is then written as a WPS used in production welding.

Question 16Code Administration, Plans and Specification Review for Structural Steel

Work that does not comply with the approved documents is found during special inspection. The inspector should do which of the following?

  1. Wait until the next scheduled site visit to act
  2. Report it promptly to the contractor and building official Correct answer.
  3. Direct the crew to make the repair at once
  4. Note it quietly in the file for inclusion in the final report later

Explanation

The special inspector's function is to observe and report rather than to direct construction. Discrepancies are documented and communicated promptly to the contractor, the engineer of record, and the building official so a resolution can be approved and the work re-inspected.

Question 17Code Administration, Plans and Specification Review for Structural Steel

Under AISC 303, the engineer of record's review of shop drawings serves which purpose?

  1. Approving the fabricator's means and methods of production
  2. Certifying the strength of every connection in the structure
  3. Checking conformance with the design concept and contract documents Correct answer.
  4. Verifying the dimensional accuracy of each fabricated member

Explanation

AISC 303 limits the review to checking that shop drawings conform to the design concept and to the information given in the contract documents. The review does not relieve the fabricator of responsibility for dimensional accuracy or for the details shown.

Question 18Code Administration, Plans and Specification Review for Structural Steel

Pre-installation verification testing under the RCSC Specification requires which of the following?

  1. Ten assemblies from each lot tested with a torque wrench
  2. One assembly per project tested in a universal testing machine
  3. All bolts of each lot tested before installation begins
  4. Three assemblies from each lot tested in a tension calibrator Correct answer.

Explanation

The RCSC Specification requires three bolt, nut, and washer assemblies from each lot to be tested in a tension calibrator to demonstrate that the selected installation method develops the required pretension. Testing is repeated when the fastener lot, installation method, or job conditions change.

Question 19Code Administration, Plans and Specification Review for Structural Steel

Which statement best describes the special inspector's authority on a structural steel project?

  1. The inspector observes and reports but does not direct Correct answer.
  2. The inspector may direct the erector's workforce
  3. The inspector may approve minor design changes in the field
  4. The inspector may waive inspection for minor members

Explanation

Special inspection is an observation and reporting function carried out for the building official, and the inspector has no authority to approve changes or to direct construction means and methods. Nonconforming conditions are reported to the contractor, the engineer of record, and the building official for resolution.

Question 20Code Administration, Plans and Specification Review for Structural Steel

Pre-installation verification testing is required for which bolted joints?

  1. Only joints assembled with direct tension indicators
  2. Pretensioned and slip-critical joints only Correct answer.
  3. Only joints using galvanized fasteners
  4. All bearing-type joints, including snug-tightened joints

Explanation

Verification testing confirms that the chosen installation method develops the required pretension, which is a design requirement only for pretensioned and slip-critical joints. Snug-tightened bearing joints are not subject to the requirement.

Question 21Structural Steel Materials, Fabrication and Component Verification

What is the specified minimum yield stress of ASTM A992 steel, the standard grade for rolled wide-flange shapes?

  1. 60 ksi (415 MPa)
  2. 36 ksi (250 MPa)
  3. 50 ksi (345 MPa) Correct answer.
  4. 65 ksi (450 MPa)

Explanation

ASTM A992 is the preferred grade for wide-flange sections and carries a minimum yield stress of 50 ksi with a minimum tensile strength of 65 ksi. The 36 ksi value belongs to ASTM A36, a general-purpose carbon steel. The 65 ksi value is A992's tensile strength, not its yield stress.

Question 22Structural Steel Materials, Fabrication and Component Verification

A connection uses 1 in. diameter high-strength bolts in standard holes. What is the required standard hole diameter?

  1. 1-3/16 in.
  2. 1-1/16 in. Correct answer.
  3. 1 in.
  4. 1-1/8 in.

Explanation

Standard holes are made 1/16 in. larger than the bolt diameter for bolts 1 in. and smaller, so a 1 in. bolt requires a 1-1/16 in. hole. Larger allowances apply only to oversize or slotted holes. A hole equal to the bolt diameter would make assembly impossible.

Question 23Structural Steel Materials, Fabrication and Component Verification

Why are match marks scribed on the nut and the projecting bolt end during turn-of-nut installation?

  1. To show the lot number of the fastener
  2. To allow nut rotation to be verified Correct answer.
  3. To identify the bolt grade after coating
  4. To record the date the bolt was installed

Explanation

Turn-of-nut installation is controlled by the amount the nut is rotated from the snug-tight condition, so match marks are struck before tightening and the relative movement is compared with the required rotation. The marks are an inspection aid, not a record of grade, date, or lot.

Question 24Structural Steel Materials, Fabrication and Component Verification

In the standard designation system for hot-rolled structural shapes, what does the prefix 'W' indicate?

  1. A structural tee
  2. A channel
  3. A wide-flange beam Correct answer.
  4. An angle

Explanation

Shape designations use a letter prefix for the product type followed by nominal depth and weight, so 'W' denotes a wide-flange section. Channels are designated 'C' or 'MC', angles 'L', and structural tees 'WT' or 'ST'.

Question 25Structural Steel Materials, Fabrication and Component Verification

What information does a mill test report (MTR) supply for a heat of structural steel?

  1. The welder qualification test records
  2. Chemistry and mechanical data for a heat Correct answer.
  3. The contractor's erection sequence plan
  4. The required bolt tension for each lot

Explanation

A mill test report documents the chemical analysis and the mechanical test results, such as yield and tensile strength and elongation, for the heat of steel it covers. It is the primary evidence that the delivered material conforms to the specified ASTM grade. Erection, bolting, and welding records are separate submittals.

Question 26Structural Steel Materials, Fabrication and Component Verification

A bolted joint is described as 'snug-tight' when:

  1. the splined end of the tension-control bolt has sheared off completely
  2. the full required turn-of-nut rotation has been applied and marked
  3. the bolt has been pretensioned to 70 percent of its minimum tensile strength
  4. the plies are in firm contact with the nut brought to full contact Correct answer.

Explanation

Snug-tight is the condition reached after a few blows of an impact wrench, or the full effort of one worker on a spud wrench, brings the plies into firm contact with the nut seated. It is not a pretensioned condition and involves no measured rotation or tension.

Question 27Structural Steel Materials, Fabrication and Component Verification

What is the role of an ASTM F436 washer in a high-strength bolted joint?

  1. It spreads the clamping load on the surface Correct answer.
  2. It indicates when the bolt has reached tension
  3. It lubricates the threads to reduce installation torque
  4. It seals the faying surface against moisture

Explanation

F436 washers are hardened circular washers placed under the turned element or bolt head to distribute the clamping force and prevent damage to the connected material. They are specified by connection geometry and hole type, not to lubricate threads or seal the joint.

Question 28Structural Steel Materials, Fabrication and Component Verification

Which heavy hex nut grade is specified for use with ASTM F3125 Grade A325 structural bolts?

  1. ASTM A563 Grade A
  2. ASTM A194 Grade 2H
  3. ASTM A563 Grade C Correct answer.
  4. ASTM A563 Grade B

Explanation

A563 Grade C heavy hex nuts are the standard match for A325 and A490 structural bolts because their proof load matches the bolt strength. A194 Grade 2H nuts are intended for high-temperature and high-pressure service, and Grade A and B nuts are lower-strength general-purpose nuts.

Question 29Structural Steel Materials, Fabrication and Component Verification

What is the maximum permitted oversize hole diameter for a 7/8 in. diameter high-strength bolt?

  1. 1-3/16 in.
  2. 1-1/4 in.
  3. 1-1/8 in. Correct answer.
  4. 1 in.

Explanation

Oversize holes are permitted to be 1/4 in. larger than the bolt diameter for bolts 7/8 in. and smaller, giving 1-1/8 in. for a 7/8 in. bolt. The 5/16 in. allowance applies only to 1 in. and larger bolts. Oversize holes are further restricted in slip-critical connections.

Question 30Structural Steel Materials, Fabrication and Component Verification

What is the minimum permitted center-to-center spacing of high-strength bolts in a connection?

  1. 2-2/3 times the bolt diameter Correct answer.
  2. 3-1/2 times the bolt diameter
  3. 3 times the bolt diameter
  4. 2-1/4 times the bolt diameter

Explanation

The minimum spacing between bolt centers is 2-2/3 times the nominal bolt diameter, with 3 times the diameter preferred for standard holes. Tighter spacing risks overstressing the material between holes and makes wrench access difficult.

Question 31Structural Steel Materials, Fabrication and Component Verification

When a calibrated wrench is used to install pretensioned bolts, the wrench setting must be verified:

  1. only once, before any bolts in the project are installed
  2. each shift, using three bolts in a calibrator Correct answer.
  3. only when a different bolt grade is introduced to the job
  4. after each group of one hundred bolts has been installed

Explanation

Calibrated wrench installation requires the wrench to be checked at least once per working shift, and after any change in fastener condition or lot, by tightening three representative bolts in a tension calibrator. This accounts for changes in lubrication, temperature, and wrench performance.

Question 32Structural Steel Materials, Fabrication and Component Verification

Which ASTM specification covers high-strength low-alloy weathering steel shapes intended for unpainted exposed structural use?

  1. ASTM A572 Grade 50
  2. ASTM A588 Correct answer.
  3. ASTM A36
  4. ASTM A500

Explanation

A588 covers high-strength low-alloy weathering steel shapes, plates, and bars that develop a protective oxide patina and are used unpainted in exposed locations. A36 is plain carbon steel, A572 Grade 50 is a non-weathering high-strength low-alloy grade, and A500 covers cold-formed hollow structural sections.

Question 33Structural Steel Materials, Fabrication and Component Verification

Which shielded metal arc welding electrode classification is normally matched to ASTM A992 steel for structural joints?

  1. E90XX
  2. E70XX Correct answer.
  3. E60XX
  4. E80XX

Explanation

A992 has a minimum tensile strength of 65 ksi, so an E70 electrode, with 70 ksi minimum tensile strength, is the usual matching filler metal and is permitted by the matching-filler-metal rules. E60 electrodes undermatched the base metal, and E80 and E90 electrodes are not typical for A992 base metal.

Question 34Structural Steel Materials, Fabrication and Component Verification

In a slip-critical connection, what slip coefficient is assigned to a Class B faying surface?

  1. 0.35
  2. 0.70
  3. 0.50 Correct answer.
  4. 0.30

Explanation

Slip-critical surface classes are defined by their mean slip coefficient: Class A is 0.30, Class B is 0.50, and Class C is 0.35. Class B surfaces, such as clean mill scale or blast-cleaned surfaces with qualified coatings, provide the highest of the commonly used values.

Question 35Structural Steel Materials, Fabrication and Component Verification

Full-size holes may be punched instead of drilled in structural steel only when:

  1. the material thickness does not exceed 3/4 in. Correct answer.
  2. the steel has been galvanized before fabrication
  3. the material thickness does not exceed 1-1/2 in.
  4. the bolt diameter is 1 in. or larger

Explanation

Punching is limited to material no thicker than 3/4 in. because thicker material produces a distorted, cracked hole with an unacceptable loss of net section. Thicker material requires drilling or sub-punched and reamed holes.

Question 36Structural Steel Materials, Fabrication and Component Verification

How is pretension verified on an installed tension-control (twist-off) bolt?

  1. By counting match marks scribed on the nut and bolt end
  2. By the sheared-off splined end and a snug washer Correct answer.
  3. By measuring the applied torque with a calibrated wrench
  4. By a feeler gauge check of the gap at the washer

Explanation

A tension-control bolt installs with a wrench that grips the splined end and turns the nut; pretension is reached when the splined end shears off at the designed tension. The inspector confirms that the splined end is gone and that the washer is in firm contact with no gap.

Question 37Structural Steel Materials, Fabrication and Component Verification

Anchor rods for column base plates are commonly specified under which ASTM designation?

  1. ASTM F436
  2. ASTM A563
  3. ASTM F1554 Correct answer.
  4. ASTM F3125

Explanation

F1554 covers anchor bolts in Grades 36, 55, and 105, which correspond to their minimum yield strengths. F3125 covers structural bolts, A563 covers nuts, and F436 covers hardened washers.

Question 38Structural Steel Materials, Fabrication and Component Verification

Hot-dip galvanizing of fabricated structural steel members is performed in accordance with which specification?

  1. ASTM A153
  2. ASTM A780
  3. ASTM A123 Correct answer.
  4. ASTM A325

Explanation

A123 covers zinc coatings applied by the hot-dip process to fabricated iron and steel products such as beams and columns. A153 applies to hardware items such as bolts and nuts, and A780 covers repair of damaged galvanized coatings.

Question 39Structural Steel Materials, Fabrication and Component Verification

Before structural welding may begin on a project, which item must be reviewed and approved?

  1. The index of approved erection drawings
  2. The bolt tension log for each connection
  3. A qualified welding procedure Correct answer.
  4. The mill test report for each heat of steel

Explanation

Welding must follow a welding procedure specification that is supported by procedure qualification test records, and the procedure must be available to the welders and the inspector. Mill reports, tension logs, and drawing indexes are separate quality records that do not authorize welding.

Question 40Structural Steel Materials, Fabrication and Component Verification

Which statement about ASTM F3125 Grade A490 high-strength bolts is correct?

  1. They must be galvanized whenever exposed to weather
  2. They are not to be hot-dip galvanized Correct answer.
  3. They may be hot-dip galvanized to ASTM A123 after threading
  4. They may be zinc electroplated in the fabricator's shop

Explanation

A490 bolts are high-strength quenched and tempered fasteners that are susceptible to hydrogen embrittlement, so hot-dip galvanizing is prohibited. Where corrosion protection is needed, coating systems other than hot-dip zinc, or a different bolt grade, must be selected.

Question 41Structural Steel Materials, Fabrication and Component Verification

With turn-of-nut installation, what nut rotation is required for a bolt whose length is six times its diameter, where the nut is the turned element over a hardened washer?

  1. 1 full turn
  2. 1/2 turn Correct answer.
  3. 2/3 turn
  4. 1/3 turn

Explanation

Required rotation increases with bolt length because a longer bolt stretches more before developing the same tension. The table calls for 1/3 turn for lengths up to four diameters, 1/2 turn for lengths over four and up to eight diameters, and 2/3 turn for lengths over eight and up to twelve diameters, so six diameters requires 1/2 turn.

Question 42Structural Steel Materials, Fabrication and Component Verification

What is the minimum bolt pretension required for a 7/8 in. diameter ASTM F3125 Grade A490 heavy hex structural bolt?

  1. 39 kips
  2. 49 kips Correct answer.
  3. 64 kips
  4. 51 kips

Explanation

Minimum pretension is tabulated by bolt diameter and grade, and for a 7/8 in. A490 bolt the value is 49 kips. A490 bolts carry higher pretension than A325 bolts of the same size because of their greater strength.

Question 43Structural Steel Materials, Fabrication and Component Verification

A new shipment of the same bolt grade arrives at the site in the middle of a pretensioned-bolt project. What is required before these bolts are installed?

  1. Only a visual check of the manufacturer's head markings
  2. Pre-installation verification testing of the new lot Correct answer.
  3. Nothing, provided the same grade was tested earlier
  4. Recalibration of every pneumatic impact wrench on site

Explanation

Pre-installation verification testing is performed for each lot of fasteners received, using a tension calibrator with a sampling of the actual assemblies to be installed. Fasteners from a different lot may behave differently because of coating, lubrication, and manufacturing variation.

Question 44Structural Steel Materials, Fabrication and Component Verification

What is the minimum tensile strength of an ASTM F3125 Grade A325 bolt with a diameter of 1 in. or less?

  1. 120 ksi Correct answer.
  2. 90 ksi
  3. 150 ksi
  4. 100 ksi

Explanation

Grade A325 bolts up to and including 1 in. diameter have a minimum tensile strength of 120 ksi, dropping to 105 ksi for larger sizes up to 1-1/2 in. The 150 ksi value corresponds to Grade A490 bolts.

Question 45Bolted Connections: Bolts, Washers, Installation and Tensioning

Snug-tight is defined as the condition in which bolts have been tightened to:

  1. the full effort of an ironworker using an ordinary spud wrench Correct answer.
  2. a torque equal to one-half turn past finger-tight
  3. fifty percent of the required minimum bolt pretension
  4. the point at which the nut can no longer be turned by hand

Explanation

Snug-tight is the tightness attained by the full effort of an ironworker with an ordinary spud wrench, or by a few impacts of an impact wrench, with the connected plies drawn into firm contact. It is the reference condition for turn-of-nut rotation but develops no specified pretension.

Question 46Bolted Connections: Bolts, Washers, Installation and Tensioning

Hardened steel washers for use with high-strength structural bolts must conform to which ASTM specification?

  1. ASTM A563
  2. ASTM F959
  3. ASTM F1852
  4. ASTM F436 Correct answer.

Explanation

ASTM F436 covers hardened steel washers, including the circular and clipped types used with high-strength structural bolts. Washers must be hardened so they do not deform under the bolt head or nut during tensioning.

Question 47Bolted Connections: Bolts, Washers, Installation and Tensioning

Structural bolts designated F3125 Grade A325 have a specified minimum tensile strength of:

  1. 100 ksi
  2. 90 ksi
  3. 120 ksi Correct answer.
  4. 150 ksi

Explanation

F3125 Grade A325 bolts are medium-strength high-strength bolts with a minimum tensile strength of 120 ksi for the common diameters. Grade A490 bolts are the 150 ksi grade.

Question 48Bolted Connections: Bolts, Washers, Installation and Tensioning

Which statement about hot-dip galvanizing of high-strength structural bolts is correct?

  1. Galvanizing of A490 bolts is permitted if they are tightened by turn-of-nut.
  2. A490 bolts shall not be galvanized. Correct answer.
  3. A490 bolts may be galvanized if the nuts are over-tapped and lubricated.
  4. Both A325 and A490 bolts may be galvanized without restriction.

Explanation

A490 bolts are prohibited from being galvanized because the pickup and subsequent tensioning of a high-strength, high-hardness bolt creates an unacceptable risk of hydrogen embrittlement. Grade A325 bolts, by contrast, may be galvanized when the assemblies are properly supplied with over-tapped or lubricated nuts.

Question 49Bolted Connections: Bolts, Washers, Installation and Tensioning

Matchmarks are placed across the nut and the projecting end of the bolt during turn-of-nut installation in order to:

  1. measure the grip length after tightening
  2. identify the lot number for test reports
  3. show that the specified rotation was applied Correct answer.
  4. record the date the connection was tensioned

Explanation

A matchmark is struck on the nut and the bolt end after snugging so that the specified rotation can be observed and verified later by inspection. Without matchmarks, there is no way to confirm that the required rotation was actually applied.

Question 50Bolted Connections: Bolts, Washers, Installation and Tensioning

A Skidmore-Wilhelm calibrator is used during bolting operations to:

  1. check the thread pitch of the bolt and nut
  2. measure the torque needed to seat a hardened washer
  3. verify the hardness of production washers
  4. determine the wrench setting that produces the required tension Correct answer.

Explanation

The calibrator measures the tension developed in a bolt as the installation tool tightens it, which establishes the relationship between tool effort and bolt tension. This relationship is what allows a calibrated wrench to be set so that the required pretension is reliably obtained.