Snap-on QJOM27A Open End Head, 27 mm for M18 Hex, J Shank (0.425″)

Description

A wide hex on a light assembly can be awkward to torque. A big socket often means a heavy wrench, yet the spec may be modest. The Snap-on QJOM27A open end head fixes that by fitting a 27 mm jaw to the J shank (0.425 in), the smallest Snap-on fitting. As a result, a short J body can handle the job.

M18 size, light load

ISO 4032 and DIN 934 both give the M18 nut a 27 mm hex. However, steel M18 joints usually call for more torque than any J body delivers. So the QJOM27A fits a different kind of job. For example, think of a brass union, a plastic pump connection, a gauge adapter or a lock collar on an adjuster. In each case the hex is wide while the spec stays low.

Which J wrench drives the Snap-on QJOM27A open end head

• QC2I75 adjustable, 5 to 75 ft-lb, 13 in long
• QC2P75 preset, 5 to 75 ft-lb, 11 in long, good for one repeat value
• QD2IN100A dual scale, 20 to 100 N·m (16.6 to 71.9 ft-lb)
• QD2IN50A dual scale, 10 to 50 N·m, for the lightest specs

In other words, the J system tops out at 75 ft-lb whichever body you pick. Snap-on also states that QD heads share a fixed pin-to-fastener sizing, so a QD body needs no length correction with the QJOM27A.

Snap-on QJOM27A open end head: the missing limit

Snap-on’s two publications disagree on this head’s maximum working torque. CAT1500i and the UK torque brochure print different values. Therefore, we leave the number out rather than risk a wrong setting. Ask Lost in HCM to confirm the limit with your quote, and then set the body at or below it.

Room around a 55 mm head

Both sources agree that the Snap-on QJOM27A open end head measures 55 mm across and 12 mm deep. So the jaw needs real side room, even on a small wrench. Before you order, swing a plain 27 mm spanner through the same path. If it clears the hose or bracket, the torque head should too. Also make sure the flats are thick enough for a full bite.

Quotes and supply for a 27 mm J jaw

SMK Vietnam lists the QJOM27A, and its partner Lost in HCM supplies it. Request a quote from Lost in HCM with your body model and target torque. For other sizes, open torque wrench heads and adaptors, or contact SMK Vietnam with questions.

27 mm J-head questions

Which heads cover 27 mm on heavier shanks?

Snap-on also lists 27 mm jaws as the QYOM27A, the QXOM27A and a Z-shank version. Each needs its own matching body, so change the wrench along with the head.

Does the QJOM27A fit a QD3IN200B?

No. The QD3IN200B has a Y shank, while the QJOM27A has a J shank. Shank sizes do not cross over.

What hex does an M18 nut use?

Both ISO 4032 and DIN 934 give M18 a 27 mm hex, which matches this jaw. Measure painted or worn parts before you rely on it.