Snap-on QJOM19A Open End Head, 19 mm for DIN M12, J Shank (0.425″)

Description

Ask a fitter for an M12 spanner and you may get an 18 or a 19. That split comes from two standards, and it matters for a torque head. The Snap-on QJOM19A open end head is the 19 mm option on the J shank (0.425 in). So it suits plants with DIN 934 hardware and many fittings at that size.

M12 in DIN sizing

DIN 934 gives the M12 nut a 19 mm hex, while ISO 4032 uses 18 mm. Older European machines, and many spare parts, still carry the DIN size. Meanwhile, newer ISO hardware needs the QJOM18A instead. Therefore, check a real nut from the job before you order the QJOM19A. A jaw that is 1 mm too big will round the corners.

Choosing a J body for the Snap-on QJOM19A open end head

CAT1500i lists several J bodies. For example, the QC2P75 presets from 5 to 75 ft-lb, and the QC2I75 adjusts across the same range. Next, the QD2IN50A covers 10 to 50 N·m, while the QD2IN100A covers 20 to 100 N·m. Pick the one whose scale puts your M12 spec near the middle. Also, every QJOM head keeps a 2.50 in pin-to-fastener distance.

What we left off and why

Snap-on’s own sources disagree on the QJOM19A. CAT1500i gives 60 ft-lb, whereas the UK brochure prints 900 in-lb, or 75 ft-lb. They also differ on width and depth. As a result, this page omits those figures. Instead, Lost in HCM confirms the limit and size with your quote, so you set the body below the real value.

Bigger shanks at 19 mm

Both sources also list the 19 mm jaw as the QYOM19A on the Y shank and the QXOM19A on the X shank. So if a high-strength M12 spec exceeds the J head, move up a shank. In that case, the QJOM19A stays on lighter jobs, such as covers, brackets and fittings.

Supply of the Snap-on QJOM19A open end head

Request a QJOM19A quote from Lost in HCM, and include your J body and the M12 spec. Lost in HCM supplies the head; SMK Vietnam lists it as a partner product. See torque wrench heads and adaptors for the 18 mm jaw, or contact SMK Vietnam.

19 mm and M12 questions

Is a 19 mm jaw right for every M12 nut?

No. DIN 934 M12 nuts use 19 mm, but ISO 4032 M12 nuts use 18 mm. Measure first.

Which torque limit applies to the QJOM19A?

Snap-on’s catalog says 60 ft-lb, and its UK brochure says 75 ft-lb. Lost in HCM confirms the right value for your order.

Can the QJOM19A work with a QD2IN50A?

Yes. It has a J shank, and the QD2IN50A is a J body.