Description
Light 3/8 in socket work often happens close to a wall, a flange or a casting rib. The Snap-on QJSD12A square drive head suits those spots. It turns a J-shank (0.425 in) torque wrench into a solid 3/8 in drive tool with a narrow 1 in head and no ratchet parts inside.
QJSD12A dimensions
| Square drive | 3/8 in, fixed |
|---|---|
| Shank | J (0.425 in) |
| Head O.D. | 1 in |
| Head depth | 1 in |
| Fastener center to retaining pin | 2.50 in (J series) |
Fixed or ratcheting at 3/8 in?
Snap-on’s 3/8 in ratcheting head for J bodies, the QJD12A-80, measures 1-1/4 in across and 9/16 in deep. By comparison, the QJSD12A is narrower at 1 in, but deeper at 1 in. So the fixed head wins where side room is tight, while the ratchet suits low overhead clearance. In addition, the fixed head has no pawl, so you lift and reset it after each swing.
Low-range J bodies for the Snap-on QJSD12A square drive head
- QC1P300 preset: 60 to 300 in-lb (6.8 to 33.9 N·m).
- QC1I200 adjustable: 40 to 200 in-lb.
- QC2I75 adjustable or QC2P75 preset: 5 to 75 ft-lb.
Preset bodies hold one value, so they suit repeat assembly on 3/8 in sockets. Meanwhile, the adjustable models cover mixed jobs on a maintenance cart.
Sockets, extensions and crowfoot work
Snap-on states that its square drive heads let a body run sockets, crowfoot wrenches and similar attachments. Note that a crowfoot moves the fastener away from the head, so the effective length changes. Therefore, check the wrench manual for the correction before you set a value. However, straight sockets and short extensions on the same axis need no such step.
Sizes beside the Snap-on QJSD12A square drive head
The QJSD8A gives J bodies a 1/4 in fixed drive, and the QJSD16A gives them 1/2 in. If your body uses a Y shank, the QYSD12A is the 3/8 in match. Snap-on prints no working torque for these fixed heads in CAT1500i, so stay within your body range and ask Lost in HCM for the head figure.
Getting the QJSD12A through Lost in HCM
Lost in HCM supplies the QJSD12A and sends the quote, while SMK Vietnam lists it. Mention the J-shank body you run, as well as your torque values. Then request a QJSD12A quote from Lost in HCM. You can also browse torque wrench heads and adaptors, or contact SMK Vietnam about the fit.
Short answers on the QJSD12A
Does the QJSD12A ratchet?
No. It is a fixed square drive. Choose the QJD12A-80 for a 3/8 in ratchet on J bodies.
Can a Y-shank wrench take it?
No. It needs a J (0.425 in) shank. The QYSD12A is the Y version.
What is the next drive size up?
The QJSD16A, a 1/2 in fixed drive for J bodies.
Reviews
There are no reviews yet.