Red Seal Tool and Die Maker flashcards

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

Lockout/tagout verification

Isolate every energy source, apply locks and tags, then confirm zero energy with a meter or gauge before any work inside the machine or die area.

Compressed air cleaning limit

Nozzle pressure for cleaning must not exceed 30 psi (207 kPa), and eye protection plus chip guards are required whenever air is used near machinery.

Cylinder separation rule

Oxygen and fuel-gas cylinders are separated by at least 20 feet or a 30-minute fire-rated barrier, stored upright, capped, and secured against falling.

Third-angle projection arrangement

In third-angle projection the top view sits above the front view and the right-side view sits to the right, the standard arrangement on North American drawings.

Feature control frame order

A feature control frame reads left to right as characteristic symbol, tolerance zone size, tolerance value, then datum references in order of precedence.

MMC bonus tolerance

Bonus tolerance equals the actual mating size minus the maximum material condition size, added to the stated geometric tolerance only when the modifier applies.

Sine bar angle formula

Sine of the angle equals the gage block stack height divided by the sine bar center distance, so a 5 inch bar at 30 degrees needs 2.5000 inches.

Micrometer thimble reading

The main scale reads in 0.025 inch increments and each thimble division adds 0.001 inch; a metric thimble with 50 divisions reads 0.01 mm per division.

Thermal expansion of steel

Steel expands about 6.5 microinch per inch per degree Fahrenheit, so a 10 inch part 10 degrees above 68 F measures roughly 0.00065 inch larger.

Tap drill size rule

For inch threads the tap drill diameter is approximately the major diameter minus one thread pitch; for metric threads it is the major diameter minus the pitch.

Grinding wheel ring test

Tap a clean, dry wheel lightly and listen for a clear ring; a dull thud indicates a crack and the wheel must be discarded, never mounted.

Hand reamer rotation rule

Reamers cut on the bevel and must turn clockwise only; reversing the rotation chips the cutting edges and ruins the hole size and finish.

Milling speed formula

Spindle rpm equals surface feet per minute times four divided by the cutter diameter in inches, because the constant four comes from twelve divided by pi.

Table feed calculation

Table feed in inches per minute equals spindle rpm times number of teeth times chip load per tooth, the basis for setting feed on a manual or CNC mill.

Lathe facing surface speed

Facing and parting run at the rpm set for the outside diameter, so surface speed falls toward the center and can cause poor finish or chatter.

Work offset relationship

Machine position equals the work offset value plus the programmed coordinate plus tool length compensation, so a wrong offset shifts every cut by that amount.

Cutter radius compensation

G41 compensates left and G42 right of the toolpath; each requires a lead-in move at least as long as the tool radius and a D register value.

Peck drilling cycle G83

G83 is peck drilling, where the Q value sets the peck depth and the tool retracts to clear chips between pecks, used for holes deeper than about three diameters.

Die clearance rule of thumb

Use roughly five to eight percent of material thickness per side for mild steel, less for harder or thinner stock, and more for soft aluminum.

Mold shrinkage calculation

Cavity size equals part size times one plus the shrinkage rate; typical rates are about 0.005 inch per inch for ABS and 0.020 for high-density polyethylene.

Three-two-one locating principle

A fixture locates with three points in the primary plane, two in the secondary, and one in the tertiary, and clamps opposite the locators rather than over them.

Tryout blue check

A uniform blue transfer across the cutting edges shows correct alignment; a heavy transfer on one corner indicates the die is out of parallel or the ram is tilted.

Press tonnage check

Required tonnage is cutting force plus stripping force plus bending or drawing force, and it must stay below about 80 percent of the press rated capacity.

Guide bushing clearance

Ball-bearing guide bushings run with about 0.0002 to 0.0005 inch clearance, while plain bushings need a light press fit and regular oil lubrication.

Hardenability versus hardness

Hardenability describes the depth to which steel hardens and is measured by the Jominy end-quench test; maximum hardness depends mainly on carbon content.

Tempering trade-off

Raising tempering temperature lowers hardness and raises toughness; some alloy steels become embrittled when tempered in the 500 to 700 F range.

Nitriding characteristics

Nitriding produces a very hard, thin case at temperatures below the transformation range, so distortion is minimal and no quench is required afterward.

Cryogenic treatment purpose

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

Punch wear diagnosis

A polished wear land is normal abrasive wear, chipping points to misalignment or insufficient clearance, and cracking suggests overload or a heat treatment problem.

Die sharpening procedure

Grind punch and die faces square, preserve the original clearance, and recheck shut height because removing stock changes the overall die height.

Welding repair preheat

Preheat according to the base steel specification, use matching filler, and re-temper after welding; skipping preheat on air-hardening steels causes cracking.

Slug pulling cause

Insufficient die clearance or a dull punch lets slugs pull upward; adding a tapered slug hole or increasing clearance corrects the problem.