HOW TO IDENTIFY YOUR LATHE THREAD SIZE FOR SUPERNOVA AND NOVA CHUCKS

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Why do you need to identify the thread size required?
There are many lathes on the market, and they all have different thread sizes on the headstock spindle. You need to know what thread size you have on your lathe so that you can get a Teknatool Chuck that will fit onto your spindle.

Parts required
None

Tools Required
1 x Vernier or measuring tool (for step 3 only if unable to complete steps 1&2 first)

Procedure
1. Firstly research your lathe manuals and pamphlet material. A good manufacturer should list the thread size clearly either in the lathe manual or in the pamphlet, preferably both.  Look for anything that specifies:

Machine Make
Machine Model
Inboard thread hand (ie Right-hand)
Outboard thread hand (ie Left-hand)
Thread Size if Known

If you don't have a lathe manual, contact your manufacturer.  You should have a manual for safety's sake, if nothing else. In the meantime, you will need to go to step 3.  

2. Refer to the Teknatool Lathe thread listing below.
Is there a match from the information you have found against the lathe thread listings? If so, this is the insert/chuck you need to match your lathe headstock spindle. If you are unable to find a match, you will need to go to step 3.

3. Measure your headstock spindle diameter.
Measuring accurately is important.
It is important to establish whether it is a metric or imperial thread ie 25.4mm corresponds to 1", 25mm is a metric thread size.
Take a piece of paper and note the measurements as you go.  Use the vernier measuring tool.

Mesure:
Outside diameter of thread
Pitch of thread
Length of thread
Register diameter
Register length

Please refer to diagram below to help with measurements required.

4. Determine thread form angle
UNC, UNF and Metric Threads are a 60° angle
Whitworth, BSW, BSF are a 55° angle.

Note: UNC threads will fit onto Whitworth Spindles, but Whitworth threads will not fit onto UNC Spindles.

5. Refer to Teknatool Thread Size Listing. Is there a match?  If so, this is the insert/chuck required to fit your lathe. Still not able to determine thread size/find a match? Go to step 6.

6. Well, you’ve tried everything, and you still can’t determine your lathe thread size. Don’t worry. You can take along a faceplate or some other threaded fitting from your headstock or an imprint of the lathe spindle size on a bit of paper to your local teknatool reseller (who will contact us) or a   local engineering company. 

Teknatool SuperNova and Nova Chuck Inserts
For threads up to 30mm or 1 1/8"  - for coarse threads over this, the chuck body has to be threaded directly - see below With the insert/adaptors below, they are screwed into the insert type SuperNova or Nova chuck body.   It becomes a relatively simple task to then remove the insert and replace with another size, should you change your lathe, without needing to go the expense of replacing your whole chuck unit.

SuperNova and Nova Chucks, Thread size threaded directly Into Chuck Body (for thread sizes over 30mm or 1 1/8")
Note: Once threaded, the chuck body can no longer take the insert adaptors or any other thread.