THREAD REFERENCE HUB

Thread charts and calculator

Calculate spindle speed, pitch, lead, thread feed and basic geometry for common thread families in Imperial or Metric units.

OPEN THREAD CALCULATOR

Thread calculator

Select the Threading tab, then choose Unified, ISO Metric, ACME, Stub ACME, NPT/NPTF or an API family.

FREE MACHINIST TOOL

Milling calculator

Tool/work diameter

in

Cutting speed

SFM

Cutting edges

count

Chip load / tooth

in

Work materialCutting tool

RECOMMENDED STARTING RANGEBroad starting guidance only—prefer the insert/tool manufacturer’s cutting data.

THREAD VALUE	COMPUTED RESULT
Selected standard
Pitch
Lead
Included angle / form
Theoretical sharp-V height
Basic external minor diameter
Basic internal minor diameter
Taper / specification note

SPINDLE1,528RPM

TABLE / TOOL FEED12.22IPM

FEED / REV0.0080in/rev

Educational starting point only. Verify against the cutting-tool manufacturer’s data, machine limits and a safe prove-out. Thread diameters are basic 60° geometry and do not include class or tolerance.

FANUC LATHE TOOL

Two-line G76 program generator

Build a reviewable starting program. Confirm your exact control format and every value before running.

Units Material Tool material Thread location Thread hand Nominal diameter Threads per inch (TPI) Final X diameter Z end Taper, radial change Radial thread height First-pass depth, radial Minimum-pass depth Finish allowance, radial Finish passes Infeed angle Maximum spindle RPM

MATERIAL SPEED STARTING RANGE

CALCULATED START RPM

THREAD CALL-OUT

Mandatory verification: Fanuc G76 address meanings and integer scaling vary by control generation and machine builder. Confirm diameter/radius conventions, P/Q scaling, taper sign, tool orientation, clearance, spindle direction, insert data and the machine manual. Never run generated code without simulation, single-block and a safe prove-out.

Thread families

UNC · UNF · UNEF

UNIFIED THREADS

60° thread form. Use TPI to calculate pitch and single- or multi-start lead.

COARSE · FINE

ISO METRIC

60° metric form. Enter pitch directly in millimetres.

GENERAL · STUB

ACME THREADS

29° power-transmission thread families. Final dimensions require the applicable standard table.

NPT · NPTF

PIPE THREADS

Tapered 60° pipe threads. Confirm gauge planes, engagement lengths and tolerances.

CASING · TUBING

API 8-ROUND

Oilfield connection family. Use the applicable API 5B table and certified gauges.

SPECIFICATION CONTROLLED

API BUTTRESS / LINE PIPE

Pitch and feed can be calculated here; final form, taper and diameters require the controlled specification.

Core thread formulas

Imperial pitch

Pitch = 1 ÷ TPI

Example: 20 TPI = 0.0500 in pitch.

Thread lead

Lead = pitch × number of starts

Threading feed

Feed per minute = RPM × lead

On controls using feed per revolution, the programmed feed normally equals thread lead. Verify the control mode and machine manual.

Important

Calculator results are educational starting points. Thread class, allowance, truncation, taper, gauge plane and final diameters depend on the exact standard and drawing. API connections require the applicable controlled API specification and certified gauges.

Latest threading guides

Hello world!
Welcome to WordPress. This is your first post. Edit or delete it, then start writing!