Snap-on QJO48ARTH Open End Head, 1-1/2″ Thin Jaw, J Shank (0.425″), 60 ft-lb Limit

Description

A standard hex nut on 1 in thread measures 1-1/2 in across flats. On conveyor take-up screws and machine adjusting rods, that nut often locks a setting rather than clamping a joint hard. The Snap-on QJO48ARTH open end head fits it with a thin jaw on a J-shank (0.425 in) body. As a result, you can apply a measured value up to its 60 ft-lb limit.

Five Snap-on heads at 1-1/2 in

• QJO48ARTH: thin jaw, J shank, 60 ft-lb.
• QYO48ARTH: thin jaw, Y shank (0.560 in), 160 ft-lb.
• QJO48A: standard jaw, J shank, 60 ft-lb.
• QYO48A: standard jaw, Y shank, 160 ft-lb.
• QXO48A: standard jaw, X shank (0.735 in), 240 ft-lb.

So the two J heads share one limit, and the thin version mainly buys access. Pick the QJO48ARTH when a flange, a frame rail or a second nut sits close behind the hex. Where the jaw has room on both sides, the standard QJO48A does the same job.

Picking a shank from the torque spec

Start with the value on the drawing. Up to 60 ft-lb, about 81.3 N·m, the QJO48ARTH on a J body covers it. Between 60 and 160 ft-lb, step up to the thin QYO48ARTH on a Y body, such as the QC3P150 preset (30-150 ft-lb). Above that, the standard QXO48A on an X body reaches 240 ft-lb. In every case, the lower of the head limit and the body range wins.

Which J wrench should carry the Snap-on QJO48ARTH open end head

The QC2I75 adjustable reads 5-75 ft-lb, and the QC2P75 preset covers the same span. In addition, the QD2IN100A dual-range body reads 20-100 N·m. Each of them can go past 60 ft-lb, therefore lock the setting at or under the head limit. A CAT1500i footnote also ties some open end heads to the QC1P100 and QC1I200 bodies, so Lost in HCM checks your pairing.

Take-up screws and the 1-1/2 in jaw

Belt conveyors keep tension with long adjusting screws, and a jam nut holds each screw in place. If one side ends up tighter, the belt can track off center. The thin QJO48ARTH jaw slides onto the nut beside the bearing housing, then the J body stops the pull at the same value on both sides. Because the jaw equals 38.10 mm, keep it for inch nuts.

Care for the Snap-on QJO48ARTH open end head

Push the jaw fully onto the flats before you pull. Then draw the handle smoothly to the signal, with no jerk at the end. Snap-on also says not to break fasteners loose with its torque tools. So free a rusted nut with a plain wrench first.

A 1-1/2 in thin jaw on order: QJO48ARTH

SMK Vietnam lists the Snap-on QJO48ARTH open end head for its partner, while Lost in HCM handles supply and pricing. Tell the team your J body model and the torque on the drawing. Then ask Lost in HCM to price the QJO48ARTH. Other jaws sit under torque wrench heads and adaptors, or you can contact SMK Vietnam.

QJO48ARTH: nut, rating and spacing

Which nut does a 1-1/2 in jaw fit?

Under ASME B18.2.2, a standard hex nut for 1 in thread measures 1-1/2 in across flats. Heavy hex nuts for that thread run larger, so measure before you order the QJO48ARTH.

Is there a thin 1-1/2 in head for higher torque?

Yes. The QYO48ARTH keeps the thin jaw but uses a Y shank, and Snap-on rates it at 160 ft-lb.

How far is the QJO48ARTH jaw from the retaining pin?

2.50 in, the spacing Snap-on gives the whole QJO series.