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M33 vs 1x8 TPI lathe chuck

Updated: October 2026

You have a lathe in the shed and a tab full of 4 inch chucks, and you are not sure whether the spindle is M33 × 3.5, 1 inch × 8 TPI, 3/4 inch × 16 TPI, or 1 1/4 inch × 8 TPI. The M33 vs 1x8 TPI lathe chuck choice is that measurement. Diameter without pitch sends the box back, and an adapter adds length in front of the bearings. The [wood lathe chuck comparison](/hub/workshop/wood-lathe-chuck) lists which listing prints which thread. We did not cut a spindle. A qualifying purchase can earn us a commission at no extra cost to you.

You have a lathe in the shed and a tab full of 4 inch chucks, and you are not sure whether the spindle is M33 × 3.5, 1 inch × 8 TPI, 3/4 inch × 16 TPI, or 1 1/4 inch × 8 TPI.

Our top picks

SIIIXS SIIIXS CK0401A1

Best overall

SIIIXS SIIIXS CK0401A1
8.6/10about £83.01
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DEEFIINE DEEFIINE k120401A1

Best value

DEEFIINE DEEFIINE k120401A1
6.6/10about £75.98
View offer
DEEFIINE DEEFIINE k120402AM33

Alternative

DEEFIINE DEEFIINE k120402AM33
6.0/10about £121.98
View offer
On this page
  1. 1.Four threads you will actually meet
  2. 2.How to check pitch without guessing
  3. 3.What the adapter in the box does, and what it does not
  4. 4.Reverse, and the ring these listings do not mention

Four threads you will actually meet

M33 × 3.5 mm is the newer UK hobby default if you are buying the lathe as well as the chuck. 1 inch × 8 TPI is eight threads per inch. 3/4 inch × 16 TPI is a smaller diameter and a finer pitch. They do not interchange. Beaufort Ink puts many Draper, Clarke and Coronet machines on 3/4 × 16, and many Axminster craft lathes on 1 × 8, and tells you to measure. Peter Child adds that a pressed-steel Clarke bed can be 3/4 × 10, so “Clarke” alone is not a thread. 1 1/4 inch × 8 TPI is a larger inch spindle. A UK review of the chuck sold on that thread says it is not M33 × 3.5. The decision order is the buying guide.

How to check pitch without guessing

Count threads against a ruler, on the crests, as Peter Child’s thread page describes, and measure the diameter across the spindle. Eight crests in one inch is 8 TPI. Sixteen is 16 TPI. A 3.5 mm pitch will not land on that inch count, which is how you separate it from 1 × 8 when both look “about an inch”. An odd spindle, such as a 1 1/2 inch Graduate, is the moment to have the thread identified rather than force a chuck on. Once you have both numbers, the best wood lathe chuck page says who each option is for.
SIIIXS SIIIXS CK0401A1

Testsieger

SIIIXS SIIIXS CK0401A1
8.6/10about £83.01
View offer

What the adapter in the box does, and what it does not

An adapter converts one stated thread to one other stated thread. Four 4 inch listings here print 1 × 8 and include a 3/4 × 16 adapter. That pair does not cover M33 or 1 1/4 × 8. The extra length moves the bowl away from the headstock bearings and adds a joint that can introduce runout. The M33 listing, a DEEFIINE at £121.98, prints M33 × 3.5 and an adapter it calls M18 × 2.5. M18 × 2.5 is not 1 × 8 or 3/4 × 16. The 1 1/4 × 8 set adapts to 1 × 8 only. The 35 mm chuck is M12 × 1 mm. Charnwood’s 32 mm insert, 1 × 8 internal to M33 at £12.50 ex VAT, is not a claim that the insert fits these bodies. Seating the chuck on the register is the mounting page.

Reverse, and the ring these listings do not mention

None of the files document an ASR groove or a locking ring. Reverse can unscrew the chuck, because it is held by the thread and the register. An adapter adds a second thread that can undo in the same way. Do not reverse the lathe to sand until the listing actually includes a lock. If you are buying the lathe now and you have no old chucks to keep, ask for M33 × 3.5 and buy the chuck in M33.

Common questions

Is M33 × 3.5 the one to buy on a new lathe?
If you are choosing the lathe as well, M33 × 3.5 is the modern UK hobby default, and you buy the chuck in that thread with no adapter. If you already own 1 × 8 faceplates and chucks, keeping 1 × 8 avoids a stack of converters. No British Standard forces the choice.
Is 1 1/4 × 8 the same as M33?
No. A UK review of the 1 1/4 × 8 set in this capture says it is not M33 × 3.5. The diameters and the pitches differ. The adapter in that box converts 1 1/4 × 8 to 1 × 8, not to M33, and the same review says there is no 3/4 × 16 adapter. “Large” is not a thread.
Does the adapter in the box make the chuck universal?
No. On four of these 4 inch listings it converts 1 × 8 to 3/4 × 16. On the M33 listing the second thread is printed as M18 × 2.5, which you should confirm. On the 1 1/4 × 8 listing it converts to 1 × 8 only. Other boxes list no adapter. One conversion is not a kit for every lathe in a shared workshop.
What does an adapter do to the bearings?
It moves the chuck further from the headstock bearings and adds a second joint. Turners treat that overhang as extra load and a possible source of runout, which is why they prefer a direct thread when they will keep the lathe. Charnwood’s 32 mm insert is still an extra joint, and it is not claimed to fit these chucks.
Do any of these chucks have a locking ring for reverse?
None of the listing files mention an ASR groove or a locking ring. Reverse can unscrew the chuck. Keep the first work in forward, with the chuck seated on the register, until you have a lock the paperwork actually includes. An adapter adds another thread that can undo.

Related pages

Wood lathe comparison

Wood lathe chuck

Best wood lathe chuck for a measured UK hobby spindle

Wood lathe chuck buying guide: measure pitch first

How to mount a wood lathe chuck: register and screw

Wood lathe chuck jaws: when the bowl still wobbles

Sources

Public UK sources used for thread, shop prices, and holding guidance. Listing prices, stars, and review counts are the amazon.co.uk lines from 16 October 2026.

  1. Peter Child: woodturning chuck threads (retrieved 16 October 2026)
  2. Beaufort Ink: lathe spindle thread look-up (retrieved 16 October 2026)
  3. UK Workshop: which spindle thread to choose (retrieved 16 October 2026)
  4. Axminster Tools: woodturning chucks guide (retrieved 16 October 2026)
  5. Axminster Tools: woodturning chuck prices (retrieved 16 October 2026)
  6. Record Power: chucking systems, jaws and spares (retrieved 16 October 2026)
  7. Yandles: Record Power SC3 chuck package (retrieved 16 October 2026)
  8. HSE WIS28: woodturning lathes (retrieved 16 October 2026)
  9. Nick Benson: holding work in a chuck (retrieved 16 October 2026)