The industrial reference library

Typical mechanical properties of common wrought aluminum alloys — strength, density, hardness, machinability, and weldability — with a spec sheet and typical uses for each grade. Compare 6061, 6063, 7075, 2024, 5052, 5083, and 3003 at a glance.

Typical properties of common stainless steel grades — type, strength, hardness, machinability, and whether it's magnetic — with a spec sheet and typical uses for each. Compare 304, 304L, 316, 316L, 303, 430, 410, and 17-4 PH at a glance.

Typical properties of the plastics machine shops cut most — Acetal, Nylon, UHMW, PTFE, polycarbonate, PEEK, HDPE, PVC, acrylic, and ABS. Compare density, strength, service temperature, moisture absorption, and machinability, with a spec sheet and typical uses for each.

The common tool steel grades at a glance — O1, A2, D2, S7, H13, M2, W1, and P20 — with AISI class, nominal composition, typical working hardness, and what each is used for. Pick the right grade for dies, punches, cutting tools, and molds.

The surface roughness reference: ISO grade numbers N1–N12 with their exact Ra in micrometres and microinches, the machining processes that produce each finish, and where each is used. Convert between Ra µm, Ra µin, and N grade at a glance.

Approximate conversions between Rockwell C (HRC), Vickers (HV), and Brinell (HB) hardness for steels, with the rough tensile strength each implies. A quick shop reference for reading across hardness scales — approximate and material-dependent, per ASTM E140.

The NPT (National Pipe Taper) reference: threads per inch, actual pipe outside diameter, and the typical tap drill for each nominal size from 1/8" to 4". Note that NPT sizes are named by nominal bore, not the measured thread diameter.

Boundary dimensions for common deep-groove ball bearings (608, 6000, 6200, 6300 series and more): bore, outside diameter, and width in millimetres, with a spec sheet per bearing. Cross-reference a bearing number to its size, or a shaft size to the bearings that fit.

Decode the AS568 o-ring dash-number system: each series (the 100s digit) fixes the cross-section, from 1/16" up to 1/4". Look up which series a dash number belongs to and its exact cross-section in inches and millimetres.

The metric fastener numbers you look up at the machine: coarse-thread pitch, tap drill (~75% thread), normal clearance hole, and socket cap-screw hex key for M2 through M20 — one spec sheet per size.

Pick the right key and keyseat for a shaft: the standard ANSI B17.1 square key size for each shaft-diameter range, with the keyseat depth cut into the shaft. From 5/16" up to 4-1/2" shafts, in inches.

A searchable thread, drill, and tap tool covering both systems in one place: Unified inch (UNC/UNF) and metric (coarse and fine). Look up thread pitch or TPI, major diameter, the tap drill for a ~75% thread, and a clearance-hole size where a reliable standard exists. Search by size (e.g. 1/4, M6) or filter by system and series.

A searchable sheet-metal gauge chart. Gauge is material-specific — the same number is a different thickness in steel, stainless, aluminum, and galvanized — so pick the material and read the real thickness in inches and millimetres. Filter by material or search a gauge (e.g. 16).

The across-flats wrench (spanner/socket) size for standard hex-head bolts and nuts, metric and inch in one searchable chart. Search a fastener size (e.g. M10, 1/2) or filter by system. Across-flats is the flat-to-flat hex dimension — the size stamped on the wrench.

The standard metric twist-drill stock series from 0.5 mm to 13 mm with the decimal-inch equivalent for each. These are true metric drills (3.0, 3.2, 3.5 mm…), not the millimetre conversions of inch drills — search a size to convert or compare.

Every 1/64" step from 1/64" to 1", with the decimal-inch and millimetre equivalent for each. Convert a fractional call-out to the decimal your caliper reads or the millimetres your CAD model uses. Search a fraction (3/8), a decimal (0.375), or a millimetre value.

The correct tap drill sizes for Unified inch threads (UNC coarse and UNF fine) at ~75% thread engagement — the shop-standard chart, with drill number/letter/fraction and decimal size for each screw size.

Decimal-inch and millimetre equivalents for the standard drill series — fractional (by 64ths), number (#1–#40), and letter (A–Z) — so you can convert any drill callout to a size you can measure or order.

Standard thread pitches for metric (ISO) coarse and fine threads in millimetres, and Unified inch (UNC/UNF) threads in threads-per-inch — with how to use a thread pitch gauge to identify an unknown thread.

The 14 geometric characteristics of GD&T (ASME Y14.5) — form, orientation, location, profile, and runout — with each symbol, what it controls, and whether it needs a datum reference. Plus how to read a feature control frame.

The common ISO 286 preferred hole-basis fits — from loose running (H11/c11) to force fits (H7/u6) — with the fit type and what each is used for, plus how the hole-basis system and IT grades work.

Standard head diameter, head height, and hex key size for inch (ASME B18.3) and metric (ISO 4762) socket head cap screws — the numbers you need to size counterbores and clearance holes.

Enter the number of holes, bolt circle diameter, and start angle — get the exact X/Y coordinate of every hole (inch or mm), clockwise or counter-clockwise, with a printable coordinate table and a scaled diagram for the shop floor.

Convert a cutting speed (SFM or m/min) and drill diameter into spindle RPM, and a feed per revolution into feed rate (in/min or mm/min) — with typical starting surface speeds by material.

Turn a cutting speed (SFM or m/min) and end-mill diameter into spindle RPM, and flute count + chip load (feed per tooth) into feed rate (in/min or mm/min) — with typical starting surface speeds and chip loads.

Convert either way between cutting/surface speed (SFM or m/min) and spindle RPM for a given diameter — the core relationship behind every speeds-and-feeds decision.

Find the extra tip length a twist drill's conical point adds, and the total depth to drill so the hole reaches full diameter at your target depth — for 118°, 135°, or any point angle.

From one chamfer leg and its angle, get the other leg and the chamfer face length — for 45° and any other angle, in inch or mm.

Enter any two of the sides or the angle of a right triangle and get the rest — the everyday shop trig for angled features, tapers, and layout.

Estimate the weight of round bar, rectangular bar, tube, hex, or sheet in common metals and plastics — inch (lb) or metric (g/kg), for one piece or many.

Find how many threads are engaged over a length and the engagement-to-diameter ratio, with typical minimum engagement by mating material so the tapped thread isn't the weak link.

Calculate the cutter depth to open a countersink to a target diameter at 82° (inch flat head) or 90° (metric) — so a flat-head screw sits flush.

Pick a socket head cap screw and get its head dimensions plus a recommended counterbore diameter and minimum depth so the head seats below flush — inch or metric.

Standard metric clearance holes (ISO 273) for a bolt through a part — close, normal, and loose fits — so the fastener passes through without binding.

Pick the right threadlocker by strength, thread size, temperature, and whether you need to remove the fastener later — a quick comparison of the common Loctite grades (purple 222, blue 242/243, red 262/271/272, green 290 wicking) with color, strength, size range, and removal.