The Proto is the pick for best overall. It took the most torque at every fitting
size: 289.5 in-lb before a 3/8-inch brake-line fitting rounded, 915.6 in-lb on a
1/2-inch coupling nut, and 1,305 in-lb on a 5/8-inch nut with only a 2.7 percent
loss on the repeat pull. It is also the one wrench here hard enough to break
rather than bend — the jaw snapped at peak torque on the 1/2-inch test — which
is the better failure of the two, because a bent flare nut wrench no longer
grips properly and starts damaging fittings. The Snap-On is the more compact
tool and the one to reach for in a tight engine bay, with the smallest head at
0.7335 inch, the tightest fit in the test at 0.465 inch, and the best average
finish of the group at 1.71; it finished 2.8 in-lb behind the Proto on the
1/2-inch nut.
For value the Williams is where it is at. At $37 it matched the Cobalt on the
brake-line fitting at 246.5 in-lb, took 848.3 in-lb on the 1/2-inch coupling nut
behind only the Proto and the Snap-On, and still returned 755.3 in-lb on the
repeat pull, an 11 percent drop. On a tighter budget the $16 Crescent set is the
buy: 0.577 inch of slop, a 0.774-inch head more compact than anything else under
$70, the widest jaw contact in the test at 9.01 mm, and 196.7 in-lb on a
brake-line fitting against 145 for a set costing fifteen times as much. Among
the cheapest wrenches the DURATECH is worth a look for holding 93 percent of its
torque on the second pull of the 1/2-inch nut.
Two results are worth taking to the store. The first is that fit, not price,
predicts damage: the Gear Wrench set pairs a compact 0.7865-inch head with the
loosest fit measured at 0.766 inch, the Mac Tools set costs $50 a wrench and
still moves 0.639 inch, and the Performance Tool set ran past the dial
indicator's one-inch range on a 3/8-inch fitting. The second is size. A flare
nut wrench earns its keep on small, soft brake and power-steering fittings,
where the good ones deliver roughly twice what an open-end can. By 5/8 inch that
advantage is gone — a flank-drive open-end wrench pulled 1,282 in-lb there, more
than every flare nut wrench except the Proto, and lost only 3.7 percent on a
second pull. Buy the flare nut set for the small stuff, and keep a good
combination wrench for everything above it.
