Red Seal Metal Fabricator flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Hierarchy of controls

Ranking of hazard controls from most to least effective: elimination, substitution, engineering controls, administrative controls, and personal protective equipment. PPE is the last line of defense.

Arc flash boundary

The distance from an arc source where incident energy equals 1.2 cal/cm², the threshold for second-degree burns. Workers inside it must wear arc-rated PPE.

Acetylene delivery limit

Acetylene must never be delivered at gauge pressure above 15 psi (103 kPa). Higher pressure can decompose the gas violently, and withdrawal is limited to about one-seventh of cylinder contents per hour.

Oxygen cylinder separation

Oxygen and fuel gas cylinders in storage must be at least 6 m (20 ft) apart or separated by a fire-rated barrier at least 1.5 m (5 ft) high with a 30-minute rating.

WHMIS 2016 label elements

A workplace label carries product identifier, hazard pictograms, signal word, hazard statements, precautionary statements, and supplier identifier. The safety data sheet has 16 sections.

Hearing conservation trigger

A hearing conservation program is required when noise exposure reaches 85 dBA over an 8-hour equivalent. With a 3 dB exchange rate, each 3 dB increase halves permissible exposure time.

Drilling RPM formula

RPM equals cutting speed times four, divided by drill diameter in inches, with cutting speed in surface feet per minute. High-speed steel in mild steel runs near 100 sfpm.

Tap drill size rule

For a 75% thread, tap drill diameter approximately equals major diameter minus one divided by the threads per inch. Choose the nearest standard drill at or below that value.

Bandsaw tooth selection

Use coarse teeth of 3 to 6 TPI for thick solid sections and fine teeth of 10 to 14 TPI for tube and thin plate. Keep at least three teeth in the cut.

Grinding wheel ring test

Suspend the wheel by its bore and tap it lightly. A clear ring indicates a sound wheel; a dull thud means the wheel is cracked and must be discarded.

Shear tonnage and material

Shear and press brake tonnage ratings assume mild steel. Multiply by about 1.4 for stainless steel and 1.5 or more for abrasion-resistant plate of the same thickness.

First-angle projection

In first-angle projection, the top view is placed below the front view and the right-side view to the left. This convention is common in ISO and CSA drawings.

Weld symbol arrow side

A weld symbol below the reference line means the weld goes on the arrow side of the joint. Above the line means the other side; on both sides means both.

Feature control frame

A geometric tolerance frame reads: the characteristic symbol, the tolerance value, and datum references in order of precedence, primary then secondary then tertiary.

Bend allowance formula

Bend allowance equals pi divided by 180, times the bend angle in degrees, times the sum of inside radius and K-factor times thickness.

Flat pattern length

Flat pattern length is the sum of outside leg lengths minus the bend deduction for each bend. Bend deduction equals twice the outside setback minus the bend allowance.

Carbon equivalent rule

Carbon equivalent equals C plus Mn/6 plus (Cr+Mo+V)/5 plus (Ni+Cu)/15. Values above about 0.40 percent indicate preheat and controlled heat input are needed to avoid cracking.

304 versus 316 stainless

Type 304 contains about 18 percent chromium and 8 percent nickel for general corrosion resistance. Type 316 adds 2 to 3 percent molybdenum for improved chloride resistance.

Aluminum 6061-T6

A heat-treatable, weldable aluminum alloy with good strength and machinability. Weld with 4043 filler for general work or 5356 for higher strength.

Material test report

A mill certificate listing heat number, chemistry, and mechanical properties for a lot of material. Match the heat number to the stamp on the plate for traceability.

Kerf

The width of material removed by a cutting process. Allow for kerf when nesting parts and laying out cuts; it is typically 1.5 to 3 mm on plasma.

Springback

The elastic recovery of metal after bending. Overbend to compensate: mild steel springs back about 1 to 2 degrees, stainless and high-strength steel about 5 to 10 degrees.

Minimum bend radius

The smallest inside radius that avoids cracking. For mild steel it is about one thickness; for 6061-T6 aluminum, roughly two to three thicknesses.

Press brake tonnage

Required bending force rises with the square of thickness for a given V-die opening. Doubling thickness roughly quadruples the force needed.

Waterjet cutting

A cold cutting process that leaves no heat-affected zone, making it suitable for heat-sensitive alloys and thick plate where thermal distortion must be avoided.

Tack weld requirements

Tacks must meet the same quality standard as the finished weld and be sized to hold the joint. Feather or remove tacks not fused into the final pass.

Distortion control methods

Balance welding about the neutral axis, use backstep or skip sequence, preset the joint, and clamp or fixture the assembly to restrain movement during cooling.

Weld shrinkage allowance

Butt welds in mild steel pull about 1 to 2 mm per metre of weld length. Add allowance when setting overall lengths before welding.

E7018 electrode meaning

E means electrode, 70 is minimum tensile strength in ksi, 1 indicates all-position use, and 8 means low-hydrogen with iron powder coating. Store in a holding oven.

Brazing temperature threshold

Brazing uses filler metal that melts above 450 degrees Celsius (840 degrees Fahrenheit) but below the melting point of the base metal. Soldering occurs below that temperature.

Magnetic particle testing

Detects surface and near-surface discontinuities in ferromagnetic materials only. It cannot be used on austenitic stainless steel or aluminum because they are not magnetic.

Liquid penetrant testing

Detects surface-breaking flaws in non-porous materials. Clean the surface, apply penetrant, remove excess, apply developer, then inspect under adequate light.

Sling angle factor

Sling capacity falls as the angle from horizontal decreases. At 30 degrees a sling carries about 50 percent of its vertical rating; at 60 degrees about 87 percent.