Red Seal Tool and Die Maker cheat sheet

Lockout/tagout requires isolating all energy sources (electrical, pneumatic, hydraulic, gravity, stored spring) and verifying zero energy with a meter or gauge before work begins.

Machine guarding rule: no operation proceeds with a guard removed unless the machine is locked out; point-of-operation, nip-point, and rotating-shaft guards are the priority classes.

Compressed-air blowgun pressure at the nozzle must not exceed 30 psi (207 kPa) for cleaning, and eye protection plus chip guards are mandatory when air is used.

Crane and hoist rule: never exceed rated capacity; the load must be within the hook's rated load at the actual reeving and boom/sling angle; tag lines control rotation.

Cylinder storage: oxygen and fuel gas separated by 20 ft (6 m) or a 30-minute fire-rated barrier; cylinders upright, capped, and secured against falling.

Pinch-point and crush hazard: die handling with a die cart or die lifter prevents hand placement under a suspended die; never place hands between closing die halves.

Noise exposure limit: 85 dBA 8-hour TWA triggers a hearing conservation program; 90 dBA is the OSHA permissible exposure limit for general industry.

Coolant mist and metalworking fluid exposure: control with enclosure, mist collector, and PPE; skin contact with rancid or contaminated coolant causes dermatitis, so concentration and pH are monitored.

Hazard communication: SDS must be accessible for every coolant, solvent, adhesive, and heat-treat salt; secondary containers are labeled with product identifier and hazard.

First-angle vs third-angle projection: third-angle places the top view above the front view and the right-side view to the right; first-angle reverses this arrangement.

GD&T feature control frame reads left to right: geometric characteristic symbol, tolerance zone diameter or width, tolerance value, then datum references in order of precedence.

MMC bonus tolerance equals the actual mating size minus the MMC size; it is added to the stated geometric tolerance only when the modifier is present.

Title-block revision control: work to the revision level on the drawing of record; superseded dimensions are void even if the shop copy shows them.

Surface finish Ra is the arithmetic average roughness; a 63 microinch Ra finish is roughly equivalent to 1.6 micrometers Ra, a common mold and die requirement.

Fit classes: clearance fit always leaves space, interference fit always has negative clearance, transition fit may be either; limits and fits tables give the allowance and tolerance.

Thread callout example: 1/4-20 UNC 2B means 0.250 in major diameter, 20 threads per inch, unified coarse, class 2 internal thread.

Weld symbols: the arrow side is below the reference line, the other side above; the tail carries the process specification, and the size precedes the symbol.

Sine bar angle: sin(theta) = height of gage blocks / sine bar center distance; a 5 in sine bar set to 30 degrees needs 2.5000 in of stack.

Gage block wringing removes the air film so the stack behaves as one solid; stack with the fewest blocks and place wear blocks at both ends.

Micrometer reading: main scale in 0.025 in increments plus thimble divisions of 0.001 in; a 40-division metric thimble reads 0.01 mm per division.

Vernier caliper resolution: main scale 1 mm with 50 vernier divisions gives 0.02 mm; inch calipers typically read 0.001 in.

Surface plate flatness grades: AA, A, and B; the plate must be supported at the specified three or four points and re-calibrated periodically.

Hole location with a coordinate measuring machine or height gage: datum-based measurement avoids stack-up error; measure from the same datums the drawing specifies.

Cylindricity and roundness are form tolerances checked with a talyrond or V-block and indicator; a V-block check reads a lobed part as a multiple of the true error.

Temperature effect: steel expands about 6.5 microinch per inch per degree F; a 10 in part 10 degrees F above 68 F is about 0.00065 in larger, so gage at 68 F for tight work.

Hand reaming removes 0.005 to 0.015 in of material per pass; reamers cut on the bevel and must turn clockwise only, never reversed, to avoid chipping.

Tapping drill size for inch threads: tap drill diameter = major diameter minus one thread pitch (approximately); for 1/4-20 that gives 0.201 in, the No. 7 drill.

Tap drill for metric threads: drill diameter = major diameter minus pitch; M8 x 1.25 uses a 6.75 mm drill.

File selection: single-cut for finishing and sharpening, double-cut for fast stock removal; draw filing produces the flattest surface on a die edge.

Hand hacksaw blade selection: 14 to 18 teeth per inch for thick stock, 24 to 32 for thin wall; at least three teeth must engage the work at all times.

Portable grinder safety: wheel rated speed must exceed the tool's no-load rpm; the guard covers at least half the wheel and the tool rest sits within 1/8 in of the wheel.

Scraping a bearing surface: blue the mating part, scrape only the high spots, and target 10 to 20 contact points per square inch for a sliding way.

Torque and clamping: clamp thin work with soft jaws or a fixture plate to avoid distortion; hand-tighten small taps with a tap guide to prevent bending.

Milling cutting speed: rpm = (cutting speed in surface feet per minute x 4) / cutter diameter in inches; the constant 4 comes from 12 / pi.

Feed per tooth rule: table feed = rpm x number of teeth x chip load per tooth; climb milling on a manual mill needs a backlash-free leadscrew or it will grab.

Lathe operations: turning speed is based on the largest diameter in the cut; facing and parting run at the spindle rpm set for the outside diameter, so surface speed falls toward center.

Drilling: spot drill to a diameter larger than the drill's web thickness so the chisel edge does not wander; peck drill deep holes to clear chips and coolant.

Grinding wheel marking: letter A to Z indicates abrasive type, grit number indicates particle size, grade letter indicates bond hardness; softer grades suit hard materials.

Surface grinder rule: dress the wheel with a diamond at the same traverse rate each time; a glazed wheel burns the work, a too-soft wheel loses form.

Tramming a milling head: sweep an indicator on a 6 to 8 in radius; adjust until the reading is within 0.0005 in over the sweep circle.

Tailstock and centers: align the tailstock with a test bar before turning between centers; misalignment shows as a taper equal to twice the offset over the length.

G90 is absolute positioning and G91 is incremental; mixing them mid-program without intent is a common crash cause.

G54 through G59 are work offsets; the machine position equals the work offset plus the programmed coordinate plus tool length compensation.

Cutter radius compensation G41 (left) and G42 (right) requires a lead-in move at least as long as the tool radius and a D register for the offset value.

Canned cycles: G81 drilling, G83 peck drilling with a Q value for peck depth, G84 tapping with an F value equal to pitch times spindle speed in feed-per-revolution mode.

Feed-per-minute versus feed-per-revolution: G94 uses inches per minute, G95 uses inches per revolution; tapping and rigid tapping almost always run in G95.

Tool length offset G43 Hn applies the tool length; the Z zero reference must be consistent between the tool setter and the program origin.

Circular interpolation G02 is clockwise and G03 is counterclockwise in the active plane; I, J, K give the arc center as an incremental vector from the start point.

Backlash and reversal: keep climb-milling direction consistent in the toolpath so the control always approaches from the same side of the cut.

Die clearance rule of thumb: 5 to 8 percent of material thickness per side for mild steel, less for harder or thinner stock, more for soft aluminum.

Punch-to-die clearance affects burr height and edge wear; too little clearance causes secondary shear and punch breakage, too much causes heavy rollover and burrs.

Stripper force is typically 5 to 20 percent of cutting force; spring selection must deliver that force at the stripped position, not at free length.

Cutting force estimate: F = shear strength x thickness x cut length; shear strength of mild steel is roughly 0.7 to 0.8 of tensile strength.

Mold shrinkage: cavity size = part size x (1 + shrinkage rate); typical rates are about 0.005 in/in for ABS and 0.020 in/in for high-density polyethylene.

Draft angle: at least 1 degree per side on mold walls, more on textured surfaces (about 1.5 degrees per 0.001 in of texture depth).

Fixture design: locate on 3-2-1 points (three in the primary plane, two in the secondary, one in the tertiary) and clamp opposite the locators, not over them.

Die shoe parallelism and punch plate alignment are checked with a dial indicator; misalignment shows as uneven die marks and rapid punch edge wear.

Tryout sequence: check shut height against the press, verify ram parallelism, set counterbalance, then bring the ram down by hand rotation before power cycling.

Blue-check the die: a uniform blue transfer across the cutting edges indicates correct alignment; a heavy transfer on one corner means the die is out of parallel or the ram is tilted.

Spring and nitrogen cylinder preload: record the preload and verify stripper travel covers the full material thickness plus 1/8 in clearance.

Guide pin and bushing fit: ball-bearing guide bushings run with 0.0002 to 0.0005 in clearance; plain bushings need a light press fit and oil lubrication.

First-piece inspection after tryout: check all drawing dimensions, burr height, and flatness; a burr over 5 percent of thickness signals a clearance or wear problem.

Press tonnage check: required tonnage equals cutting force plus stripping force plus bending or drawing force, and must stay under 80 percent of press rated capacity.

Fastener torque and thread locking: cap screws in die shoes are torqued to the size-appropriate value and secured with thread locker or dowels to resist vibration.

Austenitizing, quenching, and tempering: hardening is not complete until tempering relieves the martensite; untempered martensite is brittle and crack-prone.

Hardenability is measured by the Jominy end-quench test; it describes depth of hardness, not maximum hardness, which depends on carbon content.

Carbon content rule: hardness potential rises with carbon up to about 0.6 percent; above that, wear resistance improves but toughness falls.

Tempering temperature and hardness trade off: higher tempering temperature lowers hardness and raises toughness; avoid the 500 to 700 F range for some alloy steels due to temper embrittlement.

Tool steel families: water-hardening W, oil-hardening O, air-hardening A, high-carbon high-chrome D, shock-resisting S, hot-work H, and high-speed M and T grades.

Case hardening adds a hard surface over a tough core; nitriding produces a very hard thin case with minimal distortion because it runs below the transformation temperature.

Decarburization during heat treatment softens the surface and lowers fatigue life; control with protective atmosphere, vacuum, or packing compound.

Cryogenic treatment after quenching converts retained austenite to martensite, improving dimensional stability for gages and precision dies.

Wear diagnosis: a polished wear land on a punch edge is normal abrasive wear; chipping indicates misalignment or insufficient clearance; cracking indicates overload or heat treatment problems.

Preventive maintenance schedule: inspect cutting edges and guide bushings every production run, and record punch lengths to detect progressive wear.

Repair by welding: preheat per the base steel's specification, use a matching filler, and re-temper after welding; skip preheat on air-hardening steels and cracks form.

Die sharpening: grind the punch and die faces square, maintain the original clearance, and recheck shut height because removing stock changes the die height.

Hydraulic and pneumatic circuit troubleshooting: check pressure at the gage, then flow, then leakage; a nitrogen cylinder that will not hold pressure is a seal or fill failure.

Bearing and bushing failure: overheating, discoloration, and scoring indicate inadequate lubrication or misalignment; replace rather than rework guide bushings.

Dowel and fastener repair: ream oversized and install a larger dowel; never stake a loose dowel in a precision die because it shifts alignment.

Storage and corrosion protection: coat tooling with rust preventive, store dies on a pallet with guide posts protected, and record the last inspection date.

Personal protective equipment hierarchy: engineering controls (guards, ventilation) come first, then administrative controls, then PPE as the last line of defense.

Electrical safety: GFCI protection is required on temporary circuits and wet locations; test the GFCI before use and inspect cords for damage.

Machine shop housekeeping: chips and coolant on the floor are slip hazards; clean with a brush and pan, never with compressed air near moving machinery.

Emergency response: know the location of the eyewash station, fire extinguisher class (ABC for general shop, D for combustible metals like magnesium), and first-aid kit.

Manual lifting: keep the load close, bend at the knees, and use mechanical aids for die components over 50 lb; team lifts require a designated caller.

Geometric tolerance symbols: straightness, flatness, circularity, cylindricity are form; parallelism, perpendicularity, angularity are orientation; position, concentricity, symmetry are location; profile is either.

Datum reference frame: primary datum constrains three degrees of freedom, secondary two, tertiary one; the order changes the inspection setup.

Tolerance stack-up: worst-case analysis adds all tolerances, statistical analysis uses the root sum square; choose based on the fit's criticality.

Detail and assembly drawings: the bill of materials lists part numbers, quantities, and material; the assembly drawing shows fit and function, not manufacturing dimensions.

Geometric dimensioning on a hole pattern: a position tolerance with a diameter symbol defines a cylindrical tolerance zone centered on the true position.

Notes and specifications: general notes apply to all views unless a local note overrides; material and heat-treat callouts are mandatory for tooling parts.

Calibration interval: gages used for acceptance must be calibrated on a defined schedule and records kept; a gage out of calibration invalidates previous measurements.

Gage repeatability and reproducibility (GR&R): a rule of thumb is that the gage system should consume less than 10 percent of the tolerance for acceptable, 10 to 30 percent marginal, over 30 percent unacceptable.

Dial indicator reading: one revolution of the needle equals 0.100 in on a standard 0.001 in indicator; the small hand counts revolutions.

Height gage use: zero on the surface plate, then read the dimension; a scriber attachment marks layout lines but does not measure to the same accuracy.

Optical comparator and vision system: use for profile and angle checks on small tooling; calibrate with a certified reticle or stage standard.

Go/no-go gaging: the go member must enter the feature and the no-go must not; the gage checks the maximum and minimum material limits, not the actual size.

Drill point angle: 118 degrees for general steel, 135 degrees split point for hard materials and reduced thrust; the web must be thinned on a split point.

Hand tap types: taper, plug, and bottoming; bottoming taps have 1 to 1.5 threads chamfer and are used only after a plug tap has started the thread.

Screw extractor use: drill the recommended pilot hole, insert the extractor, and turn counterclockwise; apply penetrating oil and heat before extraction on seized fasteners.

Abrasive wheel ring test: tap a clean, dry wheel lightly and listen for a clear ring; a dull thud means the wheel is cracked and must be discarded.

Deburring: a hand scraper or deburring tool removes the burr without changing the edge geometry; files leave scratches that become stress risers on die edges.

Torque wrench use: apply force smoothly to the handle at the specified setting; a click-type wrench is accurate only in the middle 80 percent of its range.

Lathe chuck safety: never leave a chuck key in the chuck; remove it before starting the spindle, and stand clear of the rotating chuck.

Milling vise alignment: indicate the fixed jaw parallel to the table travel within 0.0005 in over the jaw length; recheck after heavy cuts.

Drill press speed: smaller drills run faster; a 1/4 in drill in mild steel runs around 1,500 rpm, a 1 in drill around 400 rpm at 100 sfm.

Surface grinder depth of cut: 0.0005 to 0.002 in per pass is typical for steel; excessive depth burns the work and loads the wheel.

Coolant application: flood coolant at the cutting zone for turning and milling; mist or air blast for grinding where flood can cause thermal shock on some materials.

Taper fits: a Morse taper holds by friction; clean both surfaces, seat firmly, and use a drift to remove; a scored taper will not hold and must be reamed.

Program verification: run a dry pass with the tool above the work, then single-block through the first part; verify offsets and tool numbers before the first cut.

G00 rapid moves: the tool moves at maximum rate and can crash; keep the rapid plane above clamps and fixtures, and use G01 for the final approach.

Subprograms and macros: M98 calls a subprogram and M99 returns; variables and macro arithmetic reduce repetitive pocket and hole-pattern programming.

Spindle and feed override: the feed override dial changes programmed feed but not rapid rate; the spindle override changes speed, which changes surface speed and tool life.

Tool wear compensation: adjust the tool length offset or wear register rather than editing the program; keep a record of offsets for each tool.

Chip load and tool deflection: long, small-diameter end mills deflect; reduce axial depth of cut and use a shorter gage length to control chatter.

Progressive die stations: pierce, form, and cutoff stations must maintain strip progression equal to the feed pitch; a pilot pin locates the strip in the final station.

Die block material: A2 air-hardening and D2 high-carbon high-chrome are common; D2 offers high wear resistance but is less tough than A2.

Mold cooling layout: cooling lines should be uniform and close to the cavity surface, typically within 1 to 2 diameters of the surface, to control cycle time and warpage.

Ejection: ejector pins must be sized and positioned on flat, strong areas; draft and polish on the core side reduce ejection force.

Fixture rigidity: support the workpiece under the cutting force; an unsupported overhang causes chatter and out-of-tolerance surfaces.

Shut height and die height: the die's shut height must match the press's shut height range; adjust with the ram and verify with the die height gage.

Assembly sequence: install guide pins and bushings first, then the punch plate and stripper, then the die block; check alignment at each stage.

Press safety during tryout: use the inch/single-stroke mode, keep hands out of the die area, and use a test strip rather than fingers to check alignment.

Noise and vibration during tryout: a rhythmic thump indicates a loose component; a sharp crack indicates punch breakage or a slug pulled up.

Slug pulling: a die with insufficient clearance or a dull punch pulls slugs upward; add a slug hole taper or increase clearance.

Tryout documentation: record the press, shut height, counterbalance, and first-piece dimensions so the next run starts from a known baseline.

Spotting and fitting: blue the mating surfaces and scrape or grind the high spots; a full bearing pattern is required before final assembly.

Steel designation: 4140 is a chromium-molybdenum alloy with about 0.40 percent carbon; 0-1 is an oil-hardening cold-work tool steel; A2 is air-hardening with about 1 percent carbon and 5 percent chromium.

Quench medium selection: water for shallow-hardening grades, oil for medium, air for air-hardening; the wrong medium causes cracking or insufficient hardness.

Annealing: heat above the critical temperature and cool slowly to soften the steel for machining; stress relieving runs below the critical temperature.

Hardness conversion: Rockwell C 60 is roughly 650 HV and about 58 to 60 HRC equivalent on the Brinell scale at high hardness; use conversion charts only for reference.

Coating selection: TiN, TiCN, and PVD coatings improve wear resistance on punches and forming tools; coating thickness is typically 1 to 5 micrometers.

Material selection for a die: match wear resistance, toughness, and hot hardness to the application; high-speed steel for hot work, D2 for abrasive wear, S7 for shock.

Root cause analysis: use the 5-why or fishbone method; a recurring punch break usually traces to alignment, clearance, or material variation, not to the punch itself.

Wear measurement: measure punch length and die opening with a micrometer and compare to the original drawing; record the trend to schedule sharpening.

Lubrication schedule: guide bushings and slides need lubrication per the manufacturer's interval; over-lubrication attracts chips and causes wear.

Corrosion and storage: humidity-controlled storage and rust preventive extend tooling life; inspect stored dies before each production run.

Spare parts inventory: keep spare punches, springs, and guide pins for high-wear stations so a failure does not stop production.

Repair documentation: record the repair method, filler material, and post-repair inspection so the next technician has the history.