InvoluteSplineGenerator

Free online involute spline calculator with DXF and PDF export

Involute Spline Generator (ISG) is a free online calculator for involute splines to ISO 4156-1:2021, ANSI B92.1-1996 and AS972B. Select the standard, number of teeth, module or diametral pitch, pressure angle (30°, 37.5°, 45°), fit and tolerance class — the app instantly draws the true tooth profile of an external spline (shaft) or internal spline (hub).

The results table shows all key spline dimensions: pitch, base, major, form and minor diameters, effective and actual tooth thickness limits, and measurement over pins or balls. Results can be shown in millimetres or inches with a single switch, which is handy when a metric ISO 4156 profile has to be compared with an imperial ANSI B92.1 one. You can create the mating profile, compare external and internal splines on one screen and check the fit visually.

What the drawing represents

The profile shown on screen — and exported to DXF — is not the nominal profile. It is drawn at mid-tolerance: halfway between maximum material condition (MMC) and least material condition (LMC). This gives a single, representative shape you can reference in CAD, rather than an idealised form that no real part ever has.

Because of that, do not measure the drawing and treat the result as a nominal dimension or as a limit. Every dimension that matters for inspection — maximum and minimum effective and actual tooth thickness, major, minor and form diameters, measurement over pins — is listed with its limits in the results table and on the PDF data sheet. Those are the values to use for tolerancing and for checking a manufactured part.

The generated profile can be downloaded as a DXF file and used directly in CAD software (AutoCAD, SolidWorks, NX, Fusion 360 and others) for design, machining or wire EDM.

PDF data sheet

Every profile can also be downloaded as a one-page PDF data sheet. It gathers everything the app calculated in a form you can print, e-mail or attach to a drawing: the input parameters, the complete table of dimensions and tolerances, and a to-scale drawing of the tooth profile with a graphic scale, so the sheet stays correct whatever size it is printed at.

Each sheet also carries a QR code that reopens exactly this profile in the app, together with the software version and the date and time it was generated — so a printed sheet can always be traced back to the settings it came from.

FAQ

What is an involute spline?

An involute spline is a shaft–hub connection whose teeth have an involute flank profile, similar to gear teeth. It transmits torque while allowing accurate centering and is defined by standards such as ISO 4156 and ANSI B92.1.

Which spline standards does the generator support?

ISO 4156-1:2021 (metric module, 30/37.5/45° pressure angle), ANSI B92.1-1996 (diametral pitch, flat root and fillet root) and AS972B.

Can I download the spline profile as a DXF file?

Yes. Every generated profile can be downloaded as a DXF file and opened in any CAD system.

Is the drawn profile the nominal size?

No. The profile on screen and in the DXF is drawn at mid-tolerance — halfway between maximum material condition (MMC) and least material condition (LMC). Use the results table or the PDF data sheet for the actual limits of each dimension, not measurements taken from the drawing.

Can I switch between millimetres and inches?

Yes. A single switch converts every dimension in the results table between mm and inch, so a metric ISO 4156 spline can be compared directly with an imperial ANSI B92.1 or AS972B one.

Can I get the results as a PDF?

Yes. The Download row offers both DXF and PDF. The PDF is a one-page data sheet with the input parameters, the full table of calculated dimensions and tolerances, a to-scale drawing of the profile with a graphic scale, the software version, the generation date and a QR code that reopens the same profile in the app.

What dimensions does the calculator provide?

Pitch, base, major, form and minor diameters, max/min effective and actual tooth thickness, fillet radius and measurement over pins or balls, including fit and tolerance class.

Is the spline calculator free?

Yes, ISG is completely free to use in the browser, with no registration.

Kostenloser Online-Rechner für evolventische Zahnwellenverbindungen nach ISO 4156 und ANSI B92.1. Berechnen Sie Zahnwellen- und Nabenprofile mit Passungen und Toleranzen und laden Sie das Zahnprofil als DXF-Datei für CAD oder als druckfertiges PDF-Datenblatt herunter.

Darmowy generator wielowypustów ewolwentowych online wg ISO 4156 i ANSI B92.1. Oblicz wymiary i tolerancje połączenia wielowypustowego (wałek i piasta) i pobierz profil jako plik DXF do CAD albo jako gotowy do druku arkusz danych PDF.