Power transmission calculator

Sprocket STEP File Generator

Generate a solid roller-chain sprocket STEP file in the browser, then download it or send the generated part directly into a Fabworks quote.

Build a laser-cut plate sprocket

Select a roller chain, then set its tooth fit, bore, and plate thickness.

Set all
rpm

Generated dimensions

Pitch diameter
2.8794 in
Outside diameter
3.1356 in
Generated root diameter
2.5628 in
Roller seat radius
0.1583 in
Chain speed
225 ft/min
Plate material
Steel 1008
Plate thickness
0.187 inRecommended fit
Chain side clearance
0.0628 in per side

ANSI roller chain dimensions

Recommended plate thickness leaves side clearance inside the chain.

ANSI #40 selected
ChainPitchRoller diameterInside widthIdeal plate
ANSI #250.250 in · 6.35 mm 0.130 in · 3.302 mm 0.125 in · 3.175 mm 0.098 in · 2.5 mm
ANSI #350.375 in · 9.525 mm 0.200 in · 5.08 mm 0.188 in · 4.763 mm 0.118 in · 3 mm
ANSI #400.500 in · 12.7 mm 0.312 in · 7.925 mm 0.313 in · 7.938 mm 0.250 in · 6.35 mm
ANSI #410.500 in · 12.7 mm 0.306 in · 7.772 mm 0.250 in · 6.35 mm 0.188 in · 4.763 mm
ANSI #500.625 in · 15.875 mm 0.400 in · 10.16 mm 0.375 in · 9.525 mm 0.313 in · 7.938 mm
ANSI #600.750 in · 19.05 mm 0.469 in · 11.913 mm 0.500 in · 12.7 mm 0.375 in · 9.525 mm

Laser-cut profile preview

The B29.1 profile uses a roller seating curve, working curve, tangent flat, and topping curve. The dashed roller shows engagement at the pitch circle.

ASME B29.1 profile

Generate the manufacturing file

100% in-browser

OpenCascade builds and reopens the STEP entirely in your browser. No dimensions, settings, or geometry are uploaded.

Laser cut it at Fabworks

We will generate the STEP if needed, add it to a new quote, and open that quote in a new tab for material, finish, and quantity.

The STEP uses the ASME B29.1 theoretical tooth form and catalog outside-diameter truncation. Manufacturing tolerances, material, heat treatment, alignment, lubrication, and application loads still require engineering review.

Quick answer

How this sprocket step generator calculator works

Choose the chain, tooth count, bore, material, plate thickness, and tooth fit to generate a single closed sprocket solid. STEP construction and validation happen locally in the browser before download or quoting.

How to use the calculator

  1. 1Select the ANSI chain size and enter tooth count, bore, tooth fit, and any intentional clearance or tip relief.
  2. 2Choose an available Fabworks plate material and a thickness that fits the selected chain.
  3. 3Review the live tooth profile and generated dimensions, then select Generate sprocket STEP.
  4. 4Download the validated file or use Order this sprocket to open a new quote with the generated STEP attached.

Worked example

Laser-cut #40 sprocket STEP

Inputs
An 18-tooth #40 roller-chain sprocket with a 0.500 in bore and an available steel plate thickness.
Result
One closed, uniform-thickness STEP solid is generated and reopened for validation.

The generated manufacturing file uses the same tooth profile, bore, and thickness shown in the preview and dimension results.

Common questions

What to know before using the result

Does STEP generation happen in the browser?
Yes. The page builds and reopens the solid locally. No separate CAD application is required to create the file.
Can I order the generated sprocket from Fabworks?
Yes. Order this sprocket creates a new quote in another tab and transfers the generated STEP file for normal material, manufacturability, and pricing review.
Is every generated sprocket suitable for service?
No. Verify hub, keyway, attachment, alignment, lubrication, material, thickness, wear, shock loading, speed, and safety requirements for the real mechanism.

Formula

Dₚ = p ÷ sin(180° ÷ N)

Pitch diameter Dₚ is set by chain pitch p and tooth count N. The generated profile follows the ASME B29.1-2011 (R2022) theoretical tooth construction: roller seating curve, working curve, tangent flat, topping curve, and catalog outside-diameter truncation.

Engineering references

Assumptions and limits

  • Presets use nominal ANSI roller-chain pitch and roller diameter values covered by ASME B29.1.
  • The browser-generated STEP is a closed, uniform-thickness plate sprocket with a round bore.
  • Nominal fit uses the standard theoretical minimum seating curve; optional clearance and tip relief are deliberate deviations for prototype tuning.
  • Hubs, keyways, bore tolerances, material, heat treatment, and high-speed applications require an engineering review.
  • Chain speed assumes the sprocket rotates at the entered shaft speed without slip.
Educational estimate
Use this result for learning and early design exploration. Verify safety-critical or production decisions with the governing standard, material data, real tooling, and a qualified engineer.

Keep designing

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STEP / DXF up to 24MB

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