Snap-on RTWH28JSL Flare Nut Head, Ratcheting 12-Point, 7/16″, J Shank (0.425″)

Description

Small tube nuts on brake, fuel and instrument lines leave little room to swing a handle. The Snap-on RTWH28JSL flare nut head handles that work at 7/16 in, the smallest size in Snap-on’s J-shank ratcheting range. Its slotted 12-point ring passes over the tube, then ratchets on the nut between strokes.

RTWH28JSL facts from Snap-on

• Size: 7/16 in, ratcheting 12-point.
• Shank: J (0.425 in).
• Fastener center to retaining pin: 3.50 in for RTWHJ heads.
• J ratcheting sizes run from 7/16 to 7/8 in. Snap-on lists no Y version at 7/16 in.

Snap-on’s data sheet also says Snap-on designs and makes this head in compliance with Boeing ST2599.

Ratcheting RTWH28JSL or a solid 7/16 in head?

Snap-on also lists the QJRXS14A, a solid 6-point 7/16 in flare nut head for J bodies, rated at 42 ft-lb. The solid head grips all six flats, so it suits soft or worn nuts. It also keeps the standard 2.50 in J spacing. The Snap-on RTWH28JSL flare nut head, by contrast, wins on speed where the swing is short and the nut needs several strokes. So choose the solid head for fragile fittings, and the ratchet for repeated assembly.

Why the longer reach matters

Standard J heads sit 2.50 in from pin to fastener, while RTWHJ heads such as the RTWH28JSL sit 3.50 in away. The extra inch adds leverage that a click scale does not account for. We found no Snap-on correction method for click bodies in the catalog. Therefore, ask Lost in HCM or Snap-on before you set one. Even the QD dual-range bodies, which skip length math for standard heads, need this check. ControlTech bodies, however, carry a built-in factor for head length.

J bodies for small line nuts

• CTECH1J240A ControlTech, 1-20 ft-lb, for light fittings.
• QD2IN50A dual-scale body, 10-50 N·m.
• QC2I75 adjustable body, 5-75 ft-lb.

Pick the body by the fitting spec, then plan the setting for the RTWH28JSL’s longer reach.

Lines that suit the Snap-on RTWH28JSL flare nut head

• Brake and fuel lines on vehicle and engine assembly.
• Gauge and instrument lines on compressors and test rigs.
• Aircraft fluid lines where a tooling list names Boeing ST2599.

Pricing the Snap-on RTWH28JSL flare nut head

SMK Vietnam lists the head, and Lost in HCM supplies it and quotes it. Give Lost in HCM your J body model, so it can advise on setup. Then request RTWH28JSL pricing from Lost in HCM. You can also compare torque wrench heads and adaptors or contact SMK Vietnam.

RTWH28JSL: short answers

Which tube nuts does a 7/16 in head fit?

It fits nuts that measure 7/16 in across flats. So measure the hex, not the tube or the thread.

Can I use it on a Y-shank body?

No. Snap-on makes the 7/16 in ratcheting head in J shank only.

Does it have a torque rating?

Snap-on’s table does not list one for ratcheting flare nut heads. Lost in HCM can check the rating for you.