I was never a fan of the 3-piece universal joints, even for hand tool use..
and yes, I worked with tools for income for many years.

A powerful impact wrench, which generally always speeds up immediately when
the load is suddenly removed, is entering a potentially hazardous area..
hazardous to the user and anyone nearby, but also risking damage to someone
else's property.

The 2-pc sockets have less joints, meaning less loss of power, and they
don't have a position where they can lock.

The 3-pc universals or sockets are generally weaker and will throw parts or
sockets when they lock, or break, and/or cause the user to figure out a
better solution.
Using a universal joint also intrduces another sloppy joint in the power
chain when a socket follows.

All accessories used on air or electric impact tools need to have locking
pins to engage the next part (not ball and detent attachment), IMO, not just
because OSHA or other agency states it.

I have the ball-joint 2-pc sockets and also the 2-pc separate universal
joints which incorporate the locking pins, and no related injuries, so
there's that part of a debate.

Much of the experience with my ball-joint type drive accessories was in a
lower power range of a 3/8" drive impact, for rapid removal of auto body
sheetmetal or used without universals for various trim panel fasteners.

Utilizing a control valve at the air inlet of an impact driver will allow
the user to limit the maximum speed of the air motor if the fastener or
drive accy suddenly disengages.
This feature is also helpful for detecting a fastener that is frozen, which
may just snap unexpectedly with full power applied.

When using 1/2" drive accessories in general, and with a ball-joint
universal, I always wear leather gloves and pay strict attention to what's
taking place at the fastener.

YMMV.. as well as the perceived usefulness of your eyes and fingers.

--
WB
..........


"Leon Fisk" wrote in message
...
Harbor Freight offers two versions of Universal Impact Joint Sets. The
first style, Item 67986 I am familiar with. Been using that style for
years in my hand sets. The second one, Item 67920 I am not. Any
advantages to the second version. Stronger, work better, horror
stories...

http://www.harborfreight.com/3-piece...set-67986.html

http://www.harborfreight.com/2-piece...set-67920.html

I'm not particularly fond of Universals, but sometimes they save the
day.

I see they have a set of Impact Wobble Socket Extensions too, that
might be a better way to go. I really like my 3/8 standard drive wobble
extensions. Would like something beefier though for use with my 1/2
inch impact wrench.

http://www.harborfreight.com/3-piece...set-67066.html

--
Leon Fisk
Grand Rapids MI/Zone 5b
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