SpecCalcsReference calculators for the shop floor
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Every value computed from the governing standard — pick your exact size and condition instead of squinting at a wall chart.

Fasteners & Threads

Bolt TorqueTightening torque by size, grade & lubrication.SAE J429 · ISO 898-1
Tap Drill SizeDrill size for any thread & engagement %.ASME B1.1 · ISO 724
Clearance HoleThrough-hole size by bolt & fit (close/normal/loose).ASME B18.2.8 · ISO 273

Machining

Cutting Speed & RPMSFM & spindle RPM by material, HSS or carbide, with feed.Machinery's Handbook
Feed Rate & Chip LoadFeed per tooth by material & diameter, with feed rate.Machinery's Handbook
Surface FinishRa ↔ Rz ↔ RMS roughness with N-grade chart.ISO 4287 · ISO 1302
Material Removal RateMRR for milling, turning & drilling.ae × ap × vf
Machining TimeCycle time from cut length, feed & RPM.T = L / (f × N)

Materials

Metal WeightWeight of bar, tube, plate & more, any material.geometry × ρ
Hardness ConversionHRC ↔ HB ↔ HV ↔ HK with ASTM E140 chart.ASTM E140-12b

Sheet Metal

Sheet Metal GaugeGauge ↔ thickness for steel, stainless & aluminium.Mfrs Std Gauge · B&S
Bend Allowance & K-FactorBend allowance, deduction & flat length by material.Machinery's Handbook

Power Transmission

Chain DriveSprocket ratio, chain length & centre distance.ASME B29.1
Spring RateCompression spring k, spring index & Wahl factor.k = Gd⁴/8D³Na

Electrical

Ohm’s LawV, I, R, P — enter any two, solve the rest.V = IR · P = IV
Voltage DropWire voltage drop & % by gauge, length & current.NEC Ch. 9 Table 8

Structural

Moment of InertiaArea second moment for 6 common cross-sections.I = πd⁴/64 · bh³/12

Unit Conversion

Pressure ConverterPSI, bar, kPa, MPa, atm, mmHg & more.ISO 80000 · NIST
Temperature ConverterCelsius, Fahrenheit, Kelvin & Rankine.NIST / ITS-90