Hamilton Intra-Matic

Most Hamilton Intra-Matic references take a 20 mm watch strap: 29 of 36. The lug width follows the case size: 38 mm case → 20 mm, 40 mm case → 20 mm and 42 mm case → 22 mm.

Shop 20 mm Shop 22 mm

Hamilton Intra-Matic lug width by case size

36 references measured. Updated 2026-10-30.

Case	Lug width	Buckle width	References	Watch strap attachment	For example
38 mm	20 mm	—	7	—	H38455131, H38455181, H38455501
40 mm	20 mm	18 mm	16	—	H38416111, H38416141, H38416160
42 mm	22 mm · 20 mm on 6	—	13	—	H38716731, H38735501, H38735751

References that take a different watch strap

H38455151: 20 mm, not the 22 mm of most 42 mm cases
H38475501: 20 mm, not the 22 mm of most 42 mm cases
H38475751: 20 mm, not the 22 mm of most 42 mm cases
H38755131: 20 mm, not the 22 mm of most 42 mm cases
H38755731: 20 mm, not the 22 mm of most 42 mm cases
H38755751: 20 mm, not the 22 mm of most 42 mm cases

Questions about the Hamilton Intra-Matic

Do all Hamilton Intra-Matic case sizes take the same watch strap?

No. The lug width changes with the case size: the 38 mm case takes 20 mm, the 40 mm case takes 20 mm and the 42 mm case takes 22 mm. Check your case diameter before you buy.

Can two Hamilton Intra-Matic watches with a 42 mm case take different watch straps?

Yes. Of the 13 Hamilton Intra-Matic references with a 42 mm case, 7 take 22 mm and 6 take 20 mm. The reference number decides, not the case size alone.