Description
Why put a 21 mm ring on a heavy X body? Because high-strength M14 bolts often need more torque than a J or Y wrench can give. The Snap-on QXXM21A box end head brings the 21 mm ISO hex to the X shank. So a gearbox or frame joint with a firm value gets a full 12-point grip without a socket stack.
QXXM21A in brief
- Opening: 21 mm, closed 12-point ring.
- Shank: X, 0.735 in.
- Ring width 31 mm, depth 13 mm.
- Pin to fastener center: 4.50 in, as on every QXXM head.
- Finish: industrial grade, as the partner lists it.
The UK torque brochure and the Lost in HCM data agree on these sizes. They differ on the maximum working torque, though. Therefore, this page leaves that figure out, and Lost in HCM confirms it on the quote.
Choosing an X wrench for the Snap-on QXXM21A box end head
| Body | Type | Range | Length |
|---|---|---|---|
| QC4P300 | Preset | 60-300 ft-lb | 27 in |
| QD3IN350A | Dual scale | 59-251 ft-lb (70-350 N·m) | 23 in |
| CTECH3X250A | ControlTech digital | 12.5-250 ft-lb | 24.1 in |
The QD3IN350A suits mixed M14 values, because QD heads need no length correction. Meanwhile, the QC4P300 holds one value for a repeat joint on a line. In both cases, set the body at or below the limit that Lost in HCM confirms for the QXXM21A.
Room around an M14 bolt row
The QXXM21A ring spans 31 mm, so it needs about 15.5 mm from the bolt center to any wall. That often beats a socket on an extension in a crowded casting. However, an X body is long, so check the swing arc as well as the ring room. For instance, a bolt next to a gearbox rib may accept the ring yet block a full pull.
Why the Snap-on QXXM21A box end head uses the X shank
Snap-on also lists 21 mm rings on J and Y shanks. Pick the Snap-on QXXM21A box end head only when the spec sits high in the range. For light or mid values, a shorter body reads more finely and tires the fitter less. Also note that DIN parts often use 22 mm for M14, so measure before you order.
Pricing the 21 mm X ring
Lost in HCM supplies this ring and prepares each quote, while SMK Vietnam lists it as a partner product. Share your X body and the M14 torque target. Then ask Lost in HCM to quote the QXXM21A on its product page. See more rings under torque wrench heads and adaptors, or contact SMK Vietnam.
QXXM21A buyer questions
Which bolt size takes a 21 mm ring?
ISO M14 hardware uses a 21 mm hex. DIN M14 parts often use 22 mm, so check first.
Does the X version carry more torque than the J version?
Yes, Snap-on’s brochure rates the X ring far higher. Even so, Lost in HCM confirms the exact limit.
Can the QXXM21A go on a QD3IN200B?
No. The QD3IN200B takes Y heads, so this ring needs an X body such as the QD3IN350A.
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