Ko-ken Z-EAL 3725Z & 3725-280 — 3/8" Drive, 72-Tooth Ratchets
🇯🇵 Made in Japan
Model Information
Model Number: 3725Z & 3725-280
Head Style: Pear Head
Drive Size: 3/8" (9.5 mm)
Tooth Count: 72-Tooth
Swing Arc: 5°
Dimensions — All Measured
Overall Length
3725Z — 178 mm (7.01 in)
3725-280 — 279 mm (10.98 in)
Head Width: 28.0 mm (1.10 in)
Working Clearance Height: 15.4 mm (0.61 in)
Working clearance height was calculated by subtracting socket thickness from the total height with a socket installed.
Weight
3725Z — 257 g (9.07 oz / 0.57 lbs)
3725-280 — 373 g (13.16 oz / 0.82 lbs)
Maximum Grip Diameter: 21.0 mm (0.83 in)
Handle Style: Comfort Grip
Finish: Full Polish Chrome
Cover Plate
Retention: Screw-Down Type
Fastener: Torx Plus IP8
It is IP8, not TX8.
TX8 can turn it, but there is noticeably more play.
Back-Drag Torque
Measured Value: 1.5–2.3 cN·m
Strength
JIS Strength Test: 202 N·m
Meets the JIS strength requirement.
Feel
Smooth, low-resistance rotation.
I don't feel any noticeable catching during rotation.
Anvil Play: Minimal
The anvil has very little play and feels highly precise.
Overall, I think these ratchets have a very good balance of strength, precision, and feel.
[OC — all measurements are my own.]