DIN 5480 Spline Calculator

Calculator Inputs

Reference diameter dB (mm)

Normal module mn (mm)

Number of teeth z

Face width b (mm)

Pressure angle

Profile shift mode

Manual profile shift x

Manufacturing method

Span teeth k

Use 0 for automatic selection.

Applied torque (N·m)

Service factor

Load sharing efficiency (%)

Allowable flank pressure (MPa)

Shaft tolerance text

Hub tolerance text

Shaft lower allowance (µm)

Shaft upper allowance (µm)

Hub lower allowance (µm)

Hub upper allowance (µm)

Example Data Table

Designation	dB mm	Module	Teeth	Face mm	Method	Auto x	Shaft tip mm
DIN 5480 - W 70 x 3 x 22 x 8f	70	3.00	22	100	Hobbing	0.11667	69.400
DIN 5480 - W 40 x 2 x 18 x 8f	40	2.00	18	60	Broaching	0.45000	39.600
DIN 5480 - W 30 x 1.5 x 18 x 8f	30	1.50	18	45	Shaping	0.45000	29.700

Formula Used

Pitch diameter: d = mn × z.

Automatic profile shift: x = (dB − d − 1.1mn) ÷ (2mn).

Base diameter: db = d × cos(30°).

Circular pitch: p = π × mn.

Base pitch: pb = p × cos(30°).

Shaft tip diameter estimate: da1 = d + 2xmn + 0.9mn.

Shaft root diameter estimate: df1 = d + 2xmn − 2hfp.

Base tangent estimate: Wk = mn cos(α)[π(k − 0.5) + z inv(α)] + 2xmn sin(α).

Backlash: minimum backlash = hub gap minimum − shaft thickness maximum.

Torque force: Ft = 2T ÷ dB, with T converted to N·mm.

Flank pressure estimate: pF = Ft × service factor ÷ active flank area.

Torque capacity estimate: Tc = allowable pressure × active area × dB ÷ (2 × service factor).

How To Use This Calculator

Enter the DIN reference diameter from the drawing or part designation.
Add the normal module, number of teeth, and face width.
Keep automatic profile shift unless your drawing gives x directly.
Select the manufacturing method for dedendum and root assumptions.
Enter torque, service factor, load sharing, and allowable pressure.
Add shaft and hub allowance values in micrometres.
Press calculate and review the result table above the form.
Download CSV or PDF for records and review notes.

DIN 5480 Spline Design Overview

DIN 5480 splines are involute connections used for compact torque transfer. They are common on shafts, hubs, couplings, pumps, drives, and machine tools. The standard uses a 30 degree pressure angle. It also links the reference diameter to the bearing friendly outside size. This makes the designation easy to match with nearby mechanical parts.

What This Tool Calculates

This calculator estimates the main planning dimensions. It finds pitch diameter, base diameter, circular pitch, profile shift, tip diameter, root diameter, tooth depth, backlash, and torque capacity. It also checks the chosen module and tooth count against the common DIN 5480 range. The result is suitable for early design work, quotations, and comparison studies.

Fit And Backlash

Spline fit depends on the actual shaft tooth thickness and hub tooth gap. The calculator lets you enter lower and upper allowance values in micrometres. It then converts them into millimetres and estimates minimum and maximum circumferential backlash. Negative minimum backlash warns that interference may occur. Final fits should always be verified with the official tables and gauges.

Torque Capacity

Torque capacity is estimated from tangential force at the reference diameter. The tool distributes that force across the active flank area. Face width, tooth count, useful flank height, load sharing, service factor, and allowable pressure are included. The result is a practical screening value. It is not a replacement for fatigue, wear, heat treatment, lubrication, or finite element checks.

Using The Results

Start with the designation from your drawing or supplier data. Enter the reference diameter, module, tooth count, and face width. Keep automatic profile shift enabled when the drawing follows the DIN reference diameter format. Choose manual shift only when you already know the coefficient. Select the manufacturing method because it changes dedendum, root radius, and form clearance assumptions. Add torque and fit allowances, then calculate.

Engineering Notes

Use conservative inputs for safety. Increase the service factor for shock loads, reversing loads, or poor lubrication. Reduce load sharing when alignment is weak or face width is long. Keep exported results with your design notes. They help compare alternatives quickly and support review meetings.

Review every production drawing with a qualified engineer. Confirm gauges before machining costly spline parts later.

FAQs

What is a DIN 5480 spline?

It is an involute spline system used for shaft and hub connections. It transfers torque through matching teeth. It is common in machinery, couplings, drives, and power transmission parts.

Why is the pressure angle fixed at 30 degrees?

DIN 5480 is commonly applied with a 30 degree pressure angle. This calculator keeps that value fixed to match the expected design family and avoid mixed standard assumptions.

What does reference diameter mean?

The reference diameter is the main size used in the designation. It helps relate the spline to nearby bearing and shaft sizes. It also helps determine profile shift.

What is automatic profile shift?

Automatic profile shift calculates x from reference diameter, module, and tooth count. It is useful when the spline follows the normal DIN designation format.

Can this replace official DIN tables?

No. It is a planning calculator. Use official tables, certified gauges, material checks, and engineering review before releasing drawings or machining final parts.

Why enter allowance values manually?

Allowance tables depend on tolerance class and fit selection. Manual allowance inputs let you use values from drawings, standards, suppliers, or inspection plans.

What does negative backlash mean?

Negative backlash means the calculated shaft tooth thickness may exceed the hub gap. That suggests interference. Review tolerances, allowances, and fit choice carefully.

How is torque capacity estimated?

The calculator converts torque into tangential force. It divides the design force by estimated active flank area. It then compares pressure against your allowable value.