Metalworking & Precision Measurement Calculators

Feeds & speeds, tolerances (ISO 286), hardness conversion (ASTM E10/E18/E92), threads (ISO 965), weld heat input, gear and spring design.

Available Tools

Calculators for the shop floor, the CMM, and the drawing board

CNC programmers, toolmakers, metrology technicians, and mechanical designers translate a print into chips, measurements, and fasteners through a surprisingly small set of recurring calculations — a spindle speed derived from surface speed and diameter, a chip-thinning correction for a low radial engagement toolpath, a torque value from a preload target, a stackup that decides whether a shaft actually fits a bore, a hardness number converted between Rockwell C, Brinell, and Vickers because the certificate and the inspection gauge do not agree. Each tool on this page implements the formula the standard or textbook actually prescribes — ISO 286 for limits and fits, ISO 1302 for surface roughness symbols, ASTM E140 for hardness conversion tables, Machinery's Handbook for thread and sine-bar geometry — and states its assumptions in the Theory section so a number on screen can be traced back to a clause, a table, or a named equation in the literature.

Who these tools are built for

The target user is a practitioner making a defensible number in minutes: a CNC programmer deciding feed per tooth for a 12 mm end mill in 4140 at 28 HRC; a process engineer estimating press tonnage for a 3 mm mild-steel bend before ordering a die set; a QA or metrology technician laying out a sine bar, stacking gauge blocks, or checking true position from a CMM report; an apprentice toolmaker converting a Brinell spec on a forging drawing to the Rockwell scale his bench tester actually reads; a design engineer sanity-checking a press-fit interference, a bolt-circle pattern, a spring rate, or a tolerance stackup on a layout before release. These calculators are deliberately not a CAM system, not a production FEA environment, and not a substitute for a qualified weld procedure — they are the arithmetic layer that sits between a handbook and a full CAE package.

Standards, handbooks, and formulas behind each tool

Results on this page follow the references practitioners already cite on drawings and in inspection reports. Limits and fits use the ISO 286 hole-basis and shaft-basis system (H7/g6, H7/p6, and related classes) with deviations drawn from the standard's tables. Surface roughness parameters (Ra, Rz) follow ISO 4287 and ISO 1302 symbology. Hardness conversion between Rockwell (ASTM E18), Brinell (ASTM E10), and Vickers (ASTM E92) uses the ASTM E140 correlation tables for steel. Threads follow the ISO 68 basic profile with tolerances per ISO 965 for metric and ANSI/ASME B1.1 for Unified inch series; thread-wire measurement uses the three-wire formula from Machinery's Handbook. Cutting calculations use the Kienzle specific-cutting-force model, Rowe's chip-thinning correction for radial engagement below the tool radius, and standard cusp-height geometry. Weld heat input follows AWS D1.1 (Heat Input = 60 × V × I / travel speed).

What these calculators are not

These are closed-form engineering calculators, not a manufacturing execution system. They do not generate G-code, post-process a CAM toolpath, or sequence a multi-setup job — they give the numbers you then type into the controller or the CAM parameter sheet. They do not predict tool life against a specific coating, substrate, and workpiece combination: feed and speed calculators return the kinematic result, not a Taylor-equation lifetime in minutes. They do not design a heat-treatment cycle, model quench distortion, or predict residual stress after welding; weld heat input is reported as an energy density, not a metallurgical prediction of HAZ microstructure. There is no sheet-metal formability (FLD) analysis, no deep-draw simulation, no springback prediction beyond empirical K-factor bending, and no finite-element stress analysis. For those workflows, use a dedicated CAM, FEA, or welding-metallurgy package; use this page for the first-order arithmetic that precedes them.