Hardware presses use various combinations of set-screw shaft collars, threading, and other mechanisms to hold hardware die sets in place.
M6 and 12mm
- Upper: M6×1.0mm thread, screwed into the press’s arbor
- Lower: 12mm solid shank, held with a set screw
Buckleguy calls this “M6 European” or “East Coast”.
1/4-24 and 12mm
- Upper: 1/4 inch, 24 threads per inch
- Lower: 12mm or 0.477 inch diameter round solid shank
1/4-24 threading is non-standard, falling between standardized SAE 1/4-20 UNC and 1/4-28 UNF. It’s sometimes written “1/4-24 UNS”, with “S” for “Special”, but even then the dimensions and tolerances vary. You won’t find 1/4-24 fasteners in hardware stores, even in the USA.
Used by many twist presses from Italy, such as those from SPS. Also used on older USMC S 5 and S 115 eyeleting machines.
3/8″ Shanks
- Upper: 3/8 inch / 9.5 mm solid shank
- Lower: 3/8 inch / 9.5 mm solid shank
Buckleguy calls this “West Coast”.
Examples:
- Little Wonder
- Craftool Hand Press (SKU 3990-01)
- TandyPro Hand Press (SKU 3960-01)
Buckleguy
- Upper: 5/16″ BSW (7.9 diameter), 1.411 mm thread pitch
- Lower: 19mm solid shank
See Also: BG 180
USMC Model C
USMC Models S-260 and S-261
- .393” shanks