Why the Tool Post Size Matters
A quick-change tool post is one of the best upgrades you can make to a lathe — it cuts tool-change time from minutes to seconds and dramatically improves repeatability. But fit is critical: the wrong size won't clamp the tool correctly and can cause chatter, poor finish, or even tool pull-out. This guide matches popular lathe models to the correct tool post size.
Understanding the Size System (T-Numbers)
Quick-change tool posts are sized by their T-number, which reflects the maximum centre height (the distance from spindle centreline to top of cross-slide). Larger T-numbers suit larger, heavier lathes.
- T30 — Mini lathes, centre height approx. 75–90 mm
- T40 — Small hobby lathes, centre height approx. 90–110 mm
- T51 — Medium lathes (Boxford, Warco WM240B), centre height approx. 125 mm
- T63 — Medium-large lathes (Colchester, Harrison, Bantam), centre height approx. 150–165 mm
- Multi Fix / T2 / T3 (Dickson Style) — Myford ML7 and Super 7
Lathe-by-Lathe Compatibility
Myford ML7 & Super 7
The Myford is the classic British hobby lathe, and it has its own tool post sizing. The correct fit for most Myford lathes is the Dickson T2 style (for the ML7) or T3 (for the Super 7 with its slightly larger cross-slide). The Multi Fix style is also compatible on some variants.
→ Dickson Style T2 Standard Holder | Quick Change Tool Post
→ Dickson Style T3 Standard Holder | Quick Change Tool Post
→ Multi Fix Quick Change Tool Post 5Pc Set
Colchester, Harrison & Bantam
These popular British workshop lathes (Colchester Student, Master, Harrison M250, Bantam) typically take a T63 tool post. The T63 set is sold as a 5-piece set and individual holders are available separately.
→ T63 Quick Change Tool Post 5Pc Set | Fits Harrison, Bantam & Colchester
→ T63 Standard Holder 4Pc Set
→ T63 Standard Holder Single Piece
Boxford & Warco (AUD, BUD, CUD Series)
Boxford lathes and the Warco WM240B use the T51 standard. This is a slightly smaller footprint than the T63 and suits the shorter centre height of these machines.
→ T51 Quick Change Tool Post 5Pc Set for AUD BUD CUD Boxford Warco
Mini Lathes (7” & 9”) — Sieg, Vevor, Max Orbit & Chinese-Made
The ubiquitous 7” and 9” mini lathes sold under many brand names (Sieg SC2, Vevor, Max Orbit, Hafco AL-250) typically accept T30 (steel) or T40 (aluminium) tool posts. The T40 aluminium version is lighter and a good choice for machines where minimal extra weight on the cross-slide is desirable.
→ T30 Quick Change Tool Post 4Pc Set for 7–9" Mini Lathes
→ T40 Mini Quick Change Tool Post Set (Aluminium)
How to Confirm the Right Size for Your Lathe
- Measure your lathe's centre height (spindle centreline to cross-slide top surface).
- Use the T-number guide above to identify your size.
- Check your existing compound rest stud thread — most use M12 or M14 but it pays to confirm.
- Still unsure? Contact our team with your lathe make and model and we'll confirm compatibility before you order.
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