Snap-on QJO52ARTH Open End Head, 1-5/8″ Thin Jaw, J Shank (0.425″), 60 ft-lb Max

Description

Machine leveling feet often use a large jam nut that locks the screw against the base. That nut can measure 1-5/8 in, yet its torque spec stays modest. The Snap-on QJO52ARTH open end head suits the job with a thin 1-5/8 in jaw on the J shank (0.425 in). Its rating in CAT1500i is 60 ft-lb, close to 81 N·m.

QJO52ARTH listing data in CAT1500i

• Opening: 1-5/8 in (41.28 mm), thin open end.
• Shank: J (0.425 in).
• Maximum working torque: 60 ft-lb (about 81.3 N·m).
• Fastener center to retaining pin: 2.50 in (QJO series).

The partner title calls this a square drive head. Snap-on, however, lists the QJO52ARTH in its thin open end table. So it grips the nut directly and takes no socket.

J or Y shank at 1-5/8 in

Snap-on makes the same opening as the QYO52ARTH on a Y shank. That twin carries 160 ft-lb at a 3.00 in spacing. Both heads cover 1-5/8 in, so the joint spec decides. A light jam nut fits the Snap-on QJO52ARTH open end head and a short body, while a firm clamp load calls for the Y version.

Short J handles that drive the Snap-on QJO52ARTH open end head

• QC2I75 adjustable, 5-75 ft-lb.
• QC2P75 preset, 5-75 ft-lb, for one value on repeat jobs.
• QD2IN100A dual scale, 20-100 N·m (16.6-71.9 ft-lb).

Each of these scales runs past 60 ft-lb, so cap the setting at the head rating. In addition, a CAT1500i footnote ties some open end heads to the QC1P100 and QC1I200 bodies only. The text we checked does not show which heads carry that mark. Therefore ask Lost in HCM to confirm your pairing.

Metric nuts near the Snap-on QJO52ARTH open end head

A 1-5/8 in jaw measures 41.28 mm across. So on a 41 mm nut it hangs loose by about 0.28 mm, and the corners can round. Snap-on’s thin metric table offers no 41 mm J head. Its standard open end table, though, lists the QYOM41 on a Y shank for true 41 mm work.

Thin-jaw upkeep on the QJO52ARTH

Thin jaws give access, yet they flex more than thick ones. So check the QJO52ARTH gap against a known nut every few months. Also seat both jaw faces fully before you pull, and keep the pull at a right angle to the handle. Finally, never use the head to free a stuck nut.

Supply of the QJO52ARTH via Lost in HCM

SMK Vietnam lists this head, and Lost in HCM supplies the QJO52ARTH and quotes it. Share your J body model and the target value. Next, reach Lost in HCM about the QJO52ARTH through its listing. More heads sit in torque wrench heads and adaptors, or you can contact SMK Vietnam.

QJO52ARTH: rating and size queries

Can the QJO52ARTH hold a 100 ft-lb spec?

No. Snap-on rates it at 60 ft-lb, so use the Y-shank QYO52ARTH, rated 160 ft-lb.

Which openings sit either side of the QJO52ARTH?

The QJO50ARTH at 1-9/16 in and the QJO54ARTH at 1-11/16 in, both J heads rated 60 ft-lb.

Does a 41 mm nut suit the QJO52ARTH?

Not well. The jaw measures 41.28 mm, so it sits loose and can round the corners.