Engineering reference
82 free engineering reference tools for the workshop — ask each one a question and get the answer, cited to the governing standard. No ads, no sign-up. Threads, machining, fits and tolerances, machine elements, materials, drawings, fabrication and inspection, each on its own shelf below.
These tools run on the same standards engines behind ASdrawn’s drawing ballooning, first article inspection and AS9102 FAIR workbooks. The governing standard text remains authoritative for inspection decisions.
Threads & fasteners
Machining
Cutting data
n = 1000·Vc ÷ (π·D) · vf = n·z·fz or n·f
Speeds and feeds calculator
Spindle speed from surface speed and diameter, or the reverse, and the feed rate and cutting time for milling, turning (with the constant-surface-speed clamp) and drilling, the cutter, bar or drill drawn turning and feeding.
hex = fz·sin κr·√(1 − (1 − 2ae/D)²) below ae = D/2
Chip thinning calculator
The chip a cutter really takes at a light radial cut or a shallow entering angle, and the feed per tooth that restores the maker's chip thickness, drawn live in plan and side view.
h = R − √(R² − (ae/2)²)
Ball-nose scallop & effective diameter
Scallop height from stepover (and the stepover for a scallop), the effective cutting diameter at a depth and tilt, and the spindle speed to cut at the right surface speed there.
Pc = vc·ap·f·kc / 60 000
Cutting power calculator
Specific cutting force by material from Sandvik and ISCAR, then the spindle power, torque and metal removal rate of a turning or milling cut, drawn against your spindle's rating.
ISO 21920-1/-2 · ASME B46.1
Surface finish (Ra)
The N1–N12 Ra grades in µm and µin, the roughness-by-process chart, turning and ball-nose cusp calculators, and the ISO 21920-1 symbol and lay.
Drilling
#80–#1 · A–Z · 1/64 · 0.1 mm
Drill sizes & reaming allowance
Every number, letter and fractional drill in inch and mm with the nearest metric drill, a finder for the drills either side of any size, and the stock to leave for a reamer.
L = (d/2) / tan(θ/2)
Drill point, countersink & counterbore depth
The depth to program for a drill's point, a countersink's Ø on or off a hole, with a flat or a pilot, and a counterbore to seat a head, drawn live in section.
Tooling
ISO 1832 / ISO 5608
Insert & holder decoder
Type CNMG 120408 or PCLNR 2525M 12 and get every field decoded, with the insert's shape, clearance and tolerances, or the holder's style and geometry, drawn.
ISO 296 · ISO 7388-1 · ISO 12164-1 · ISO 15488
Tool holder tapers & ER collets
Morse, 7/24 (SK, BT, CAT) and HSK-A shank sizes with their gauge Ø and taper, and ER collet clamping ranges, with the shank drawn true to its taper and how each is held.
ISO 525
Grinding wheel marking decoder
Type a wheel's marking (A 46 K 5 V) and get the abrasive, grain size, grade, structure and bond decoded, with the wheel's grains, bond and pores drawn magnified in proportion, and the spindle speed limit for its Ø.
Turning, EDM & G-code
tan α = (D − d) / 2L
Taper turning calculator
The top-slide angle, included angle, 1:k ratio and taper per foot from a taper's diameters and length, or the small Ø from the taper, and the tailstock set-over, drawn to scale.
o = d/2 + g
Wire EDM offset calculator
The wire offset (wire radius plus spark gap), the kerf, the smallest inside corner radius and the wire's path across a punch or a die, with makers' gaps for rough, skim and finish cuts, drawn to scale.
Fanuc · Siemens
G-code and M-code reference
Paste a block and read what each word does on a Fanuc mill, a Fanuc lathe or a Siemens, see the move drawn with its arc centre and radius, and compare the common codes side by side.
Fits & tolerances
ISO 286-1 / -2
Fits & limits calculator
Hole/shaft limit deviations and the resulting clearance, transition, or interference fit — computed from ISO 286.
ISO 2768 / DIN 7168
General tolerances (ISO 2768)
The ± band for any untoleranced size or angle, and the zone width for geometrical tolerances, by class, from ISO 2768-1 (current) and the withdrawn ISO 2768-2 and DIN 7168 (legacy).
Worst-case · RSS
Tolerance stack-up calculator
Worst-case and RSS totals over a chain of dimension contributions, with each contributor listed.
TP = 2·√(ΔX² + ΔY²)
True position calculator
Ø position from X/Y deviations — with MMC/LMC bonus tolerance and a pass/fail verdict against the frame.
Machine elements
Shafts & hubs
DIN 6885-1 / ISO R773
Keyway & key sizes
Enter a shaft diameter for its parallel key, then pick the key, the shaft or the bore (hub) to see its width, depth and limits at a free, normal or close fit.
DIN 471 / DIN 472
Retaining ring (circlip) grooves
Pick a shaft or bore and its diameter: the groove Ø and width to cut with their tolerances, the ring's thickness, the least margin to the end and the load capacities, drawn to scale.
DIN 509 / ISO 18388
Relief grooves (undercuts)
Pick a form and a diameter: the undercut's radius, depth and lengths for normal or fatigue loads, and the least countersink on the mating part, drawn at the shoulder with the grinding wheel.
ISO 866 / ISO 2540 / ISO 2541 · ISO 6411
Centre holes & drawing symbols
Pick a form and a size: the hole's diameters and depth, the centre drill that makes it, and how the drawing calls it up (required, may remain, must not remain), drawn with the centre engaged.
DIN 5480 · ISO 4156
Involute spline sizes: DIN 5480 & ISO 4156
Enter a spline designation for its pitch, tip and root diameters and the measurement over or between pins, with the shaft drawn in its hub.
Bearings & seals
ISO 286 shaft & housing classes
Bearing shaft & housing fits
Pick a bearing type, its load and the ring the load rotates relative to for the recommended shaft and housing classes, with both seats worked out for your bore and OD and drawn.
ISO 15 boundary dimensions · ISO 281 L10
Bearing number decoder
Type a bearing number such as 6205-2RS1 C3 for its type, bore, outside diameter and width, seals, clearance in µm and precision class, drawn in section, with its basic L10 life from C, P and speed.
AS568 · face and radial glands
O-ring groove dimensions
Enter an AS568 dash number for its face-seal gland depth, groove width and squeeze, or your own gland, and see squeeze, fill and stretch checked and drawn.
ISO 6194-1 · DIN 3760 rotary shaft seals
Shaft seal housing & shaft design
Enter a lip seal's d1 × D × b for its housing bore and shaft: H8 and h11, surface finish, hardness, bore depth and lead-in chamfers, as the seal makers give them, drawn in section.
Pins, drives & springs
ISO 2338 / ISO 8734
Dowel pin & hole sizes
Enter a dowel's nominal diameter for its m6 or h8 pin limits and its reamed hole, then pick a mating hole class to see the fit it gives, drawn to scale.
ISO 54 modules · involute
Gear calculator: module, centre distance, span & over pins
Enter the module (or diametral pitch) and the tooth counts for the pitch diameters and centre distance, with profile shift, and the span or over-pins measurement that checks a tooth, drawn in mesh.
ISO 606 chains · belt pitch length
Belt length & chain links calculator
Enter the pulleys or sprockets and the centre distance for the belt's pitch length or the chain's links, or the length for the centre distance, with the drive drawn to scale.
Helical springs · round wire
Spring rate calculator: compression & extension
Enter the wire, the outside diameter, the coils and the free length for the rate, the solid height, the load at a working length and the stress, with the spring drawn compressing.
Geometry
x = R·cos θ, y = R·sin θ
Bolt circle calculator
X/Y coordinates for every hole in a bolt-circle pattern, from diameter, count, and start angle.
Law of sines / cosines
Triangle solver
Right and oblique triangles from any valid combination of sides and angles — SSS, SAS, ASA, SSA.
R = (c² + 4h²) / 8h
Chord, arc & radius calculator
Radius from a chord and height, circle through 3 points, arc length and included angle.
H = L·sin θ
Sine bar calculator
Gauge block stack height for an angle on a sine bar or plate — and the angle from a measured stack.
Materials
Grades & specs
AS/NZS · EN · AISI/SAE · AA · UNS · JIS
Material grade equivalents
Pick a steel, aluminium, copper alloy or titanium grade for its nearest equivalents across AS/NZS, EN name and number, AISI/SAE or AA, UNS and JIS, with the compositions drawn side by side. Only designations two publishers agree on.
AMS / ASTM
Materials & coatings lookup
AMS and ASTM material specs with a superseded-spec resolver, plus common coating and plating callouts.
Ensinger · MCAM · Victrex · DuPont · Chemours · Röchling
Machining plastics: speeds, feeds and tool angles
Pick acetal, nylon, PEEK, UHMW-PE, PTFE or G10 and the operation for the cutting speed, feed and tool angles its makers publish, side by side, with the spindle speed at your diameter, coolant, annealing and expansion, and the cutting edge drawn.
Weight & allowances
m = ρ·V
Stock weight calculator
Bar, tube, plate, and ring weight from dimensions and material density — metric and imperial.
MIL-PRF-8625 · AMS 2404 · AMS 2460
Coating & plating allowance
Pick a coating and enter the finished size and tolerance of a shaft, bore, slot or face: the size to machine to before coating, with the build-up, penetration and the tolerance band drawn.
ΔD = α·D·ΔT
Shrink fit temperature
Pick an interference fit, the material and the clearance wanted at assembly for the temperature to heat the hub or cool the shaft to, drawn opening; or bring a size measured warm to 20 °C.
Hardness, heat & corrosion
ASTM E140
Hardness conversion
Pick a From and a To scale to see Rockwell C, Vickers and Brinell side by side, each test method drawn, with the conversion and approximate tensile strength for non-austenitic steels (ASTM E140 Table 1, ASTM A370).
Mill data sheets · Harris case depth
Heat treatment temperatures by grade
Pick a grade for its hardening and tempering temperatures, each data sheet's range side by side, drawn as a heat treatment cycle, with temper colours and carburised case depth.
MIL-DTL-14072E anodic index · MIL-STD-889D
Galvanic corrosion & anodic index
Pick a fastener and the part it goes in for which metal corrodes, the anodic index difference against the limit for its exposure, and what to do about a pair that is not compatible, drawn on the scale and at the joint.
Drawings & symbols
ASME Y14.5 · ISO 286
Drawing callout decoder
Paste a hole, thread, fit or frame callout and read every symbol and number in plain English, with the hole drawn in section to scale and each piece linked to its reference.
ASME Y14.5 · ISO 1101
GD&T symbols & modifiers
Build a feature control frame and see its tolerance zone drawn and read in plain English, with every characteristic symbol, datum and material-condition modifier, and ASME↔ISO equivalents.
AWS A2.4 / ISO 2553
Weld symbol reference
Build a weld symbol and see it drawn the AWS way and in ISO System A and B, with every symbol beside its joint section and the supplementary symbols.
ISO 13715
Edge condition symbol reference
Read an edge symbol: what +, − and ± allow on an external or internal edge, the burr or undercut size and direction, drawn as the zones about the ideal corner.
ISO 5456-2 · ISO 128-2 · AS 1100.101
First and third angle projection and line types
Where each view goes in first and third angle projection, the projection symbol, section A–A and the line types with their ISO numbers and AS 1100 letters, on a drawing that moves.
Fabrication
Sheet & plate
BA = A·(R + K·t)
Sheet metal bend allowance calculator
Bend allowance, outside setback, bend deduction and the flat blank for a part with one bend or several, the neutral axis drawn at K·t.
F = 1.42·Rm·t²·L / V
Press brake tonnage calculator
Air-bending force per metre and for the bend length, the V-die rule of thumb, the natural inside radius and the minimum flange, checked against a press's capacity.
MSG · galvanised · US Std · B&S
Sheet metal gauge chart
Gauge 7 to 30 in millimetres and inches for steel, galvanised, stainless and aluminium, drawn side by side to scale, the nearest gauge for a thickness, and the mass of a square metre.
F = L·t·τ
Punching force calculator
The force and tonnage to punch a round, square, rectangular or slotted hole, or shear a straight cut, with the punch, sheet and die drawn in section and the shape in plan, checked against your press.
Developed geometry
Cone, fish-mouth and lobster-back layout calculator
Flat patterns for a cone or frustum, the fish-mouth template for a branch on a header, and the mitre cuts of a lobster-back bend, drawn assembled and unrolled to scale, with the template ordinates at twelve stations.
Sections & pipe
AS/NZS 3679.1 · AS/NZS 1163
Structural steel sections (UB, UC, PFC, angles, SHS, RHS, CHS)
Every Australian universal beam and column, channel, angle and structural hollow section with its dimensions, Ix, Zx, Sx and r, drawn to scale with its axes, and the mass of the length you cut.
ASME B36.10M · ASME B36.19M · ASME B16.5 · AS 2129
Pipe schedule chart (sch 40, sch 80, stainless) and flange drilling
Outside diameter, wall and bore for every NPS 1/8 to 24 in each schedule, carbon and stainless, the mass and water per metre, and the drilling of Class 150 and 300 and Table D and E flanges, drawn end on.
Welding
φvw = φ·0.6·fuw·tt·kr
Fillet weld size and capacity calculator
The throat of an equal or unequal fillet, its design capacity per millimetre to AS 4100, the weld metal it takes per metre, and the smallest fillet AS 4100 allows on the plate, drawn in section.
Tp = 697·CET + 160·tanh(d/35) + 62·HD^0.35 + (53·CET − 32)·Q − 328
Weld preheat calculator (CET method, heat input, carbon equivalent)
The minimum preheat for a structural steel from its analysis, the plate thickness, the consumable's hydrogen and the heat input, each term's share drawn beside the joint, with the carbon equivalents and the heat input from volts, amps and travel speed.
Inspection & quality
MIL-STD-105E / ANSI/ASQ Z1.4 / ISO 2859-1
AQL sampling plan calculator
Enter the lot size, inspection level and AQL for the code letter, how many to inspect, and the accept and reject numbers, with the arrows in the master table followed and the OC curve drawn.
Cpk = min(USL − x̄, x̄ − LSL) / 3σ
Cp and Cpk calculator
Cp, Cpk, Pp and Ppk with the expected ppm out of each limit, from a mean and σ or from pasted measurements, with the fitted curve drawn against the limits.
ISO 3650 · makers' sets
Gauge block stack calculator
The fewest blocks from your gauge block set that make a size, metric or inch, with wear blocks at both ends, and the stack drawn to scale.
ISO/R 1938 system
GO / NO-GO gauge tolerance calculator
Plug, ring and gap gauge sizes for an ISO hole or shaft class: the new GO gauge, the size it wears out at, and the NO-GO, with the zones drawn to scale.
AIAG MSA · ISO 14253-1
Gauge R&R calculator
EV, AV, GRR, PV, %GRR and ndc from a crossed study's readings, by the AIAG MSA Average and Range or ANOVA method, with the range chart; and the conformance decision for a measured value.
Maintenance & fluid power
% = Brix × factor
Coolant concentration & top-up calculator
Concentration from a refractometer's Brix reading and the coolant's factor, the litres of concentrate and water that bring a sump to its target, and mix ratios both ways.
ISO VG · SAE · NLGI · ASTM D341
Oil viscosity & grease grade calculator
Enter an oil's 40 °C and 100 °C viscosities for its grade and its viscosity at the working temperature, drawn on a viscosity-temperature chart, or a grease's worked penetration for its NLGI grade.
SAE J514 · J1453 · BSP · NPT · DIN 2353
Hydraulic fitting identification by thread size
Enter the thread diameter you measured, the pitch and the seat angle to name a hose or pipe fitting (JIC, ORFS, ORB, SAE 45°, BSP, NPT, metric 24°), with the matched end drawn and its look-alikes.
F = p·A · v = Q / A
Hydraulic & pneumatic cylinder force calculator
Enter the bore, rod and pressure for the push and pull force, the pump's flow for the speed and stroke time, or the cycles a minute for a pneumatic cylinder's free air use, with the cylinder drawn in section.
SKF TKSA 20 · Fenner
Shaft alignment tolerance & V-belt tension calculator
Enter the speed and the four alignment readings to check them against an alignment-tool maker's table, with the shafts drawn, or the pulleys and centre distance for a V-belt's deflection and setting force.
I = P / (√3·U·cos φ·η)
Motor current & torque calculator
Enter the motor's kW, the supply, the power factor and the efficiency for its full-load current, or the torque and speed for its power, with the power triangle drawn and makers' IE3 motor tables.
Utilities
SI ↔ inch
Machinist unit converter
Length, angle (DMS), temperature, pressure, torque, force, speed, mass, and roughness conversions.
1/64 · #80–#1 · A–Z · mm
Decimal equivalents chart
Fractions to decimal inches and mm and back, the nearest 64th, 32nd, 16th or 8th drawn on a steel rule, and every drill to 1 in on a one-page wall chart to print.
deg / rad
Scientific calculator
Keyboard-first expression calculator with trig in degrees or radians.
cost = setup/q + run + material
Job cost calculator
Machine-hour rate, set-up and cycle time, material, scrap and markup to a cost and price a part, drawn against the batch size, with a price break table.