Description
Some torque jobs never need a ratchet. A crowfoot on a line nut, a socket on a test joint, or a single final pull all work with a solid drive. The Snap-on QXSD16A fixed head gives an X-shank wrench exactly that: a 1/2 in square with no pawl inside.
Fixed QXSD16A against the ratcheting QXD16A
| QXSD16A (fixed) | QXD16A (ratcheting) | |
|---|---|---|
| Drive | 1/2 in | 1/2 in |
| Shank | X (0.735 in) | X (0.735 in) |
| Head O.D. | 1 in | 1-5/8 in |
| Depth | 1-1/4 in | 3/4 in |
| Ratchet service kit | None | RKRS80A |
In short, the fixed head is narrower but deeper. So it reaches into tight side spaces, while the ratchet suits low overhead room. In addition, the fixed head has no pawl, so the drive carries no ratchet play.
Where the Snap-on QXSD16A fixed head earns its place
- Crowfoot work on hydraulic and fuel lines, where the attachment sets the angle.
- Final torque on a joint that a speed tool already ran down.
- Audit checks, where one controlled pull is all you need.
Snap-on states that its fixed square drive heads let the bodies work with sockets, crowfoot wrenches and similar attachments. So the Snap-on QXSD16A fixed head acts as the link between an X body and that tooling. A crowfoot changes the effective length, though, so follow your wrench manual for the correction.
Torque capacity and X bodies
Snap-on’s UK torque brochure gives the QXSD16A a 3,000 in-lb limit, which is 250 ft-lb or about 339 N·m. As a result, that figure lines up with the X bodies Snap-on sells.
- CTECH3X250A ControlTech: 12.5 to 250 ft-lb.
- QD3IN350A dual-range: 70 to 350 N·m (59 to 251 ft-lb).
- QC4P300 preset: 60 to 300 ft-lb, so never set it above 250 ft-lb with this head.
Other fixed 1/2 in heads
Snap-on also builds 1/2 in fixed heads for other shanks: the QJSD16A for J and the QYSD16A for Y. Meanwhile, on the X shank, the QXSD24A and QXSD32A carry 3/4 in and 1 in drives. Therefore, match the shank to your body first, then the drive to your sockets. Among them, the QXSD16A is the 1/2 in choice for X bodies.
Looking after a fixed drive
A fixed head has few parts, yet the square still wears. Check the QXSD16A drive corners for rounding before each shift. Also keep the shank clean so it locks without play. Never use the head to break a fastener loose, and recalibrate the body on schedule.
Buying the Snap-on QXSD16A fixed head
Lost in HCM supplies the QXSD16A and quotes it, while SMK Vietnam lists it. Name your X body and the attachments you plan to run. Then request a QXSD16A quote from Lost in HCM. You can browse X bodies under torque wrenches, as well as more heads under torque wrench heads and adaptors. For fit questions, contact SMK Vietnam.
QXSD16A questions
Why choose a fixed head over a ratchet?
It has no pawl, a smaller 1 in O.D. and no service kit to stock. So choose it when you do not need to swing back.
What is the QXSD16A torque limit?
Snap-on’s UK brochure lists 3,000 in-lb, which equals 250 ft-lb.
Does the QXSD16A fit a Y-shank body?
No. Use the QYSD16A for Y bodies.
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