The Lock Washer Effect may occur when the AGD Adjustable-Style
Thread Ring Gage Locking
Mechanism is loosened.
When an AGD Adjustable-Style Thread Ring Gage is threaded it is
a solid ring without adjustment slots. After the AGD Adjustable-Style
Thread Ring Gage is hardened and threaded, the adjustment slots
are cut into the AGD Adjustable-Style Thread Ring Gage and the locking
mechanism is installed. The AGD Adjustable-Style Thread Ring Gage
is then finished lapped and set to a Threaded Master Setting Gage.
When the steel is hardened, the modules are trapped in stasis. When
the steel is machined the molecules relax and as they relax they
cause movement in the work piece. When the workpiece is a ring,
like a thread ring gage, and a slot is cut clean through from the
outside diameter to the inside diameter there will be movement of
the steel. The movement may be very minor and not even visible to
the unassisted eye, but in the case of gages, movement of 0.0005"
(0.0127mm) is considered significant.
The movement will manifest itself in one or two of three ways:
1. The slot will be wider than the cut width. The ring has sprung
open.
2. The slot will be narrower than the cut width. The ring has sprung
closed.
3. The slot will have a helical offset. This is the lock washer
effect.
With the locking mechanism in place all of these deformations are
forced back to their original, pre-slotted condition by the process
of setting the AGD Adjustable-Style Thread Ring Gage to a Threaded
Master Setting Gage. If the locking mechanism is loosened, the AGD
Adjustable-Style Thread Ring Gage has the tendency to spring back
to its deformed state. Any time the locking mechanism is loosened,
the AGD Adjustable-Style Thread Ring Gage needs to be re-set on
the appropriate Threaded Master Setting Gage and again locked into
place.
Some of the known reasons for AGD Adjustable-Style Thread Ring
Gages to go out of calibration:
1. Wear: This is the #1 reason.
2. Mis-handling: Dropping; Using as hockey puck; Throwing against
wall; Make-up your own here.
3. Exposure to temperature extremes: Frozen in hold of an airplane
or heated by sitting in a hot truck.
4. Faulty locking mechanisms which allow the threaded ring gage
to mis-adjust for no visible reason. This is very rare.
Conclusions:
1. Whenever you use AGD Adjustable-Style Thread Ring Gages it is advisable
to have a Threaded Master Setting Gage available to verify the AGD
Adjustable-Style Thread Ring Gage has not gone out of tolerance.
2. Whenever you adjust an AGD Adjustable-Style Thread Ring Gage, the
adjustment must be accomplished with a Threaded Master Setting Gage.
Gage Crib Worldwide, Inc.
6701 Old 28th St SE, Suite B
Grand Rapids, MI 49546-6937
Phone: 001-616-954-6581 • Fax: 001-616-954-6583 CONTACT FORMS & INFO
