Reference charts and calculators

54 tools, last reviewed 2026-08-16

Sizes, torque figures, conversions and sizing calculators for the jobs that come up on a bench or a site. Every figure here is taken from a published standard, and the standard is named on the page so you can check it.

Hydraulics & pneumatics

Hydraulic Hose Size Chart

Hydraulic hose size chart with dash numbers, inside diameter in inches and mm, and the flow each size carries at safe velocity. Plus how to read a hose layline.

O-Ring Size Chart

O ring size chart covering AS568 cross-sections and dash numbers plus metric sizes, with the compression figures that decide whether a seal holds.

Air Compressor CFM Calculator

Size an air compressor from the tools you actually run, with a CFM calculator, a tool consumption chart at 90 psi and the SCFM to CFM conversion.

Cylinder Force Calculator

Work out push and pull force for a hydraulic or pneumatic cylinder from bore, rod diameter and pressure, with a force table for common bores.

Air Fitting Types Chart

Air line coupler profiles compared, why they do not interchange, and how to size air hose so you keep the pressure at the tool.

Pump Head Calculator

Calculate total dynamic head from lift, discharge height, friction and outlet pressure, then the pump horsepower needed, with the formulas and a friction loss table.

Pressure Washer Nozzle Chart

Pressure washer nozzle colours and spray angles, what each is for, and how to pick the orifice size number from your machine PSI and GPM.

Solenoid Valve Types

Solenoid valve types explained: direct acting against pilot operated, normally open and closed, port counts and how to pick one for water, air or oil.

Fasteners & threads

Socket Size Conversion Chart

SAE vs metric socket and wrench size chart with decimal equivalents, showing which conversions actually fit and which will round off a fastener.

Bolt Torque Chart

Bolt torque specs for SAE grade 2, 5 and 8 fasteners in ft-lb, dry and lubricated, plus the torque formula and the tightening sequences that stop warped joints.

Tap Drill Size Chart

Tap drill size chart for metric coarse, UNC and UNF, and NPT pipe threads, with clearance hole sizes and the formula for any thread not listed.

Metric Bolt Size Chart

Metric bolt dimensions with pitch, head size, hex key size and torque by property class, including the ISO and DIN head sizes that differ at M10 and M12.

Thread Identification Chart

Identify an unknown thread from its diameter, pitch and angle, with a comparison of UN, metric, BSP, NPT and JIC and the traps that look alike.

Torx Size Chart

Torx bit sizes from T1 to T100 with point-to-point dimensions in mm and inches, which T size fits which screw, and the difference from Torx Plus and security Torx.

Bolt to Wrench Size Chart

Match bolt thread size to spanner or socket size for SAE and metric hex heads, with heavy hex and the two metric standards that disagree at M10 to M14.

Power transmission

Bearing Size Chart

Ball bearing size chart with bore, outside diameter and width for the 6000, 6200 and 6300 series, plus how to decode a bearing number and its suffixes.

V-Belt Size Chart

V belt size chart with top width and height for A, B, C, D, 3V, 5V, 8V and SPZ to SPC sections, plus how belt length numbering works and how to cross reference.

Roller Chain Size Chart

ANSI roller chain size chart with pitch, roller diameter, width and tensile strength, plus the ISO British equivalents and how chain numbering works.

Oil Seal Size Chart

Oil seal sizes by shaft diameter with common metric dimensions, seal type codes and the material temperature limits that decide which compound to fit.

Retaining Ring Size Chart

Retaining ring and circlip sizes to DIN 471 and DIN 472 with groove dimensions, plus the difference between external, internal, E-clip and spiral rings.

Pulley Speed Calculator

Work out driven pulley speed from drive diameter and rpm, or the pulley size you need for a target speed, with belt speed and the ratio formulas.

Gear Ratio Chart

Gear ratio from tooth counts, what the ratio does to speed and torque, common sprocket combinations, and how final drive ratio combines with the gearbox.

Electrical

Wire Size Calculator

Work out wire gauge from amps and distance, with the NEC 310.16 ampacity table for copper and the small-conductor breaker limits that override it.

Conduit Fill Chart

EMT conduit dimensions and the maximum number of THHN conductors each size takes at 40 percent fill, straight from NEC Chapter 9 and Annex C.

Motor HP to Amps Chart

Convert motor horsepower to amps with NEC full-load current tables for single and three phase, plus what FLA means and why the nameplate differs.

Ohms Law Calculator

Enter any two of volts, amps, ohms and watts and get the other two, with the Ohms law and Watts law formulas and worked examples for finding resistance and current.

DC Wire Size Chart

DC wire size chart for 12 and 24 volt systems by current and run length at 3 percent voltage drop, with AWG ampacity from 22 AWG up and the voltage drop formula.

Generator Sizing Calculator

Work out what size generator you need from what actually runs at once, with running and starting watts for common loads and what a 3,500 watt generator can power.

Extension Cord Gauge Chart

Extension cord gauge by amps and length, why a long thin cord kills a tool, and how to read the jacket markings so you buy the right cord for the job.

Pipe, fittings & flanges

NPT Thread Size Chart

NPT thread dimensions with outside diameter, threads per inch and tap drill for each size, plus how to tell NPT from BSPP before it leaks.

BSP Thread Chart

BSP thread chart with outside diameter and threads per inch for every size, plus the difference between BSPP and BSPT and how to tell BSP from NPT.

Pipe Schedule Chart

Pipe schedule chart with outside diameter and wall thickness for schedule 10, 40 and 80, and why nominal pipe size never matches the measurement.

Flange Dimensions Chart

ASME B16.5 flange dimensions with outside diameter, bolt circle, bolt count and bolt size for Class 150 and 300, plus the correct bolt tightening sequence.

Metalworking & abrasives

Sandpaper Grit Chart

Sandpaper grit chart comparing FEPA P grades with CAMI numbers and particle size in microns, plus which grit to use at each stage of a job.

Speeds and Feeds Calculator

Milling speed and feed calculator with surface speeds by material for HSS and carbide, and chipload figures by cutter diameter.

Sheet Metal Gauge Chart

Sheet metal gauge chart in inches and mm for steel, galvanised, stainless and aluminium, with the reason the same gauge number is a different thickness in each.

Hardness Conversion Chart

Hardness conversion chart between Rockwell C and B, Brinell and Vickers, with approximate tensile strength and which scale to use on which material.

Grinding Wheel Chart

Decode a grinding wheel marking, pick the right abrasive and grade for the material, and check the maximum safe speed before you fit it.

304 vs 316 Stainless Steel

304 and 316 stainless compared on composition, yield strength and corrosion resistance, with how to read the markings and when 316 is worth the premium.

Aluminium Grades Chart

Aluminium alloy series explained with strength, weldability and corrosion resistance for 5052, 5083, 6061, 6082 and 7075, and which grades survive at sea.

Welding

Welding Rod Chart

Welding rod chart decoding the AWS E-number, with amperage ranges by electrode diameter for 6010, 6011, 6013, 7018 and 7024.

MIG Wire Size Chart

MIG wire size chart matching wire diameter to material thickness, with starting voltage and wire speed settings and which shielding gas to run.

Tungsten Electrode Chart

TIG tungsten electrode colour chart with the oxide in each type, what to use on steel and aluminium, amperage by diameter and how to grind the tip.

Lifting & rigging

Sling Angle Calculator

Work out the real tension in each sling leg from the load and the angle, with the ASME B30.9 load angle factors and hitch capacity reductions.

Shackle Size Chart

Shackle working load limits by size for Grade 6 screw pin and bolt type shackles, with the side-load reductions and inspection points that matter.

Wire Rope Capacity Chart

Wire rope sizes with minimum breaking strength and working load limits for 6x19 and 6x36 IWRC rope, plus D/d ratio and inspection criteria.

Power tools

Hammer Drill vs Impact Driver

Hammer drill, impact driver and drill driver compared on mechanism, torque and what each is for, with a plain verdict on which to buy for masonry, screws and steel.

Brushless vs Brushed Motor

Brushless and brushed motors compared on efficiency, runtime, maintenance and cost, with the honest answer on when brushless is worth paying for.

Cobalt vs Titanium Drill Bits

Which drill bits actually cut stainless and hardened steel: cobalt, titanium-coated and plain HSS compared on what they are made of and how long they last.

Circular Saw Blade Size Chart

Circular saw blade sizes from 85mm to 350mm with bore, kerf and maximum rpm, tooth counts by material, 115mm and 125mm angle grinder disc sizes and which blades are safe on which machine.