Contact Us
(877) 248-1631
A shop-floor reverse lookup that ranks published spline sizes from a tooth count, major diameter, optional minor, and over-pins — then points you to custom carbide spline inserts.
Most spline jobs do not stall because the insert cannot be ground. They stall because nobody can say, with a straight face, what spline is on the bench.
The print is missing. The print is worn. The print is in a standard the shop has never cut. A hub might be ANSI B92.1. A shaft might be DIN 5480. A hydraulic spare might still be legacy DIN 5482. Tooth count alone is not enough. Major diameter can be worn or chamfered. Two standards can look almost the same until you check space width, tooth thickness, and a pin measurement.
CNC Broach Tools™ already quotes and grinds custom carbide spline broach inserts for CNC lathes and mills. The new Instant Spline Identifier & Reverse Lookup is built to answer that first question on the shop floor, then send you to the same quoting page we use for spline inserts: https://cncbroachtools.com/cnc-spline-broach/.
What Instant Spline Identifier & Reverse Lookup actually does
It does not invent a designation. It searches published sizes and ranks likely matches so you can confirm the form before you request inserts.
That is the difference between guessing a DP and a fit class from a caliper reading, and comparing a shop measurement to ANSI B92.1, DIN 5480, and DIN 5482 in the same lookup. Results come back ranked Strong / Likely / Possible. That ranking is on purpose. DIN 5480 and withdrawn DIN 5482 can look similar. The tool is meant to put both on the table instead of hiding one of them.
Each candidate shows the designation, diameter bands, recommended pin, and the calculated over-pins or between-pins range for that size. If the list is long, add minor diameter or tighten slack. Then open the matching size in the Involute Spline Calculator to confirm diameters, fit class, and inspection dimensions before you quote or cut.
How to use it
Open the Involute Spline Calculator and choose Instant Spline Identifier & Reverse Lookup. It is currently in beta test.
1. Say hub or shaft. Internal and external catalogs are different. Pick the one that matches the part in your hand.
2. Count the teeth. That is the first filter.
3. Measure major diameter with a micrometer or caliper.
4. Add minor diameter if the major is worn, chamfered, or hard to trust.
5. Optional: measure over pins (shaft) or between pins (hub). The tool fills a recommended pin size from the teeth and major. Use a different pin if that is what is in the kit.
6. Set slack if the part is used or the measurement is not a clean print dimension.
7. Tap Identify spline.
You do not need a perfect print to get a useful list. You do need honest measurements. If the major is chewed up, say so with slack and a minor. If you can get a pin reading, use it. That is the measurement shops already use to verify a part.
DIN 5480, DIN 5482, and dimension over pins
The same calculator now supports DIN 5480 (current European metric, module and reference diameter) and DIN 5482 (legacy metric, still common on hydraulic, agricultural, and spare parts), alongside ANSI B92.1.
Inspection math is in the results, not a separate spreadsheet:
- Recommended pin for the spec, including larger DIN 5480 shaft pins on low tooth counts
- Over pins on external splines
- Between pins on internal splines
Instant Spline Identifier & Reverse Lookup uses the same pin logic as the calculator, so a shop measurement can be compared to a published size instead of guessed from major diameter alone.
That matters when two catalogs are close. A worn major can point at the wrong family. A pin check usually separates them.
From unknown part to a broach quote
CNC Broach Tools sells only to end users. Spline inserts are a special grind with a three-insert minimum. Typical lead time is 21-28 days to ship, with expedite options.
The intended path is simple:
1. Identify the unknown spline in Instant Spline Identifier & Reverse Lookup.
2. Confirm the designation and pin dimensions in the calculator.
3. Send the data with the drawing — or the sample — through the contact form at https://cncbroachtools.com/contact-us/.
If you already know it is ANSI B92.1, you can still use the Involute Spline Configurator on the spline broach page and copy that data into your quote request. Start here: https://cncbroachtools.com/cnc-spline-broach/.
If the part still has no published standard, we continue to offer optical reverse engineering of splines, gears, and serrations. That service is for parts the lookup cannot rank — not a replacement for counting teeth and measuring the major first. Read more: https://cncbroachtools.com/reverse-engineering-splines-and-gears-accurate-spline-measurement-and-broaching-tool-quotes/.
What to send with the quote
The cleaner the package, the faster we can tell you whether a carbide insert in a standard CNC holder will cut it. Include:
- Hub or shaft (internal or external)
- Tooth count
- Major and minor diameters, and whether they are worn
- Pin size used, plus over-pins or between-pins if you have it
- The ranked designation from Instant Spline Identifier & Reverse Lookup, if you got a Strong or Likely match
- Length of cut, material, and whether the spline is blind or through
- The drawing if you have one, or a photo and a sample if you do not
If you need a refresher on how a data block is supposed to read, this older post still applies: https://cncbroachtools.com/decoding-a-spline-data-block-essential-information-for-your-spline-broach-quote/.
A note from the shop
“Most spline delays are not tooling delays. They are identification delays. If you can count the teeth and measure the major, we can rank the published sizes that fit — including DIN and over-pins. Then we can talk about whether a carbide insert in a standard CNC holder will cut it.”
— Shane Anderson, VP of Operations, CNC Broach Tools
Try it, then get a quote
Instant Spline Identifier & Reverse Lookup, DIN 5480 / DIN 5482 calculation, and over-pins / between-pins inspection are in the CNC Broach Tools Involute Spline Calculator now.
Learn more and request a spline insert quote: https://cncbroachtools.com/cnc-spline-broach/
Questions or a part on the bench: https://cncbroachtools.com/contact-us/
