Poppet Links vs. Split Links
(one-piece links vs.
Bill Tingley, Vice President & General Manager, Bend Tooling Inc.
Twenty years ago Bend
Tooling Inc. developed and refined the only line of poppet links available
for mandrel tube-bending. Poppet links
replace the many varieties of split links,
an older design that was developed after World War II. The split link
design was a compromise of the link’s effectiveness with the limitations of
metallurgical and machining technologies of that time. However, modern
materials and computer-controlled machining have eliminated the need for
this compromise by making possible the ideal design for links, the poppet
These are the advantages
of Bend Tooling’s poppet link over the split link:
The poppet link is
much stronger than the split link.
The simple reason for this is that the poppet link is solid not split,
therefore, all of the link bears the load of tube-bending instead of
just half of it.
poppet link is more durable than the split link.
It is tougher and can absorb a shock better than the split. This is
because the split link, to make up for the lack of strength in design,
must be made of harder steels that are brittle and so more likely to
The poppet link has a
heavy-duty detent system compared to the split link. The detent system makes the mandrel balls snap
back into a straight line upon retraction from the completed tube bend.
Because the head of the split link is broken up into three separate
pieces, there is no clearance for anything but a small detent system,
which wears out faster than the detent system for Bend Tooling’s poppet
Because of these
three factors, the poppet link has a longer life than the split link.
Because the poppet
link is simpler in design, it requires less time to manufacture.
Therefore, the poppet link is considerably less expensive than the
Longer life combined
with lower price means that the per-bend cost of the poppet link is a
fraction of that of the split link.
Also, the poppet
link is easier to inventory than the split link. Because of the
lack of precision in its manufacture, each half of a split link must be
matched with the other for proper assembly. If the halves are separated
and mixed up with others, the split link is no good.
poppet link is easier to assemble than the split link. It requires
only simple, readily available tools – an arbor press, a ball-joint
fork, and a pair of retaining ring pliers – all of which can be supplied
by Bend Tooling. Furthermore, because of the longer life of the Bend
Tooling poppet link, the need for assembly is less frequent compared to
the split link.
The poppet link is the
ideal design for rotary-draw tube-bending, and modern machining and
materials technologies have now made it possible. Switching over to the
poppet link is worth the effort, because doing so will save you time, money,
and headaches. For additional information about poppet links, including
assembly instructions, see our technical article
"Assembly of Mandrels with Poppet-Style
Past Technical Articles
SPECIFYING MATERIALS FOR TUBE-BENDING TOOLS
THE WIPER FEATHERED EDGE
POPPET LINKS VS. SPLIT LINKS
THE "FORWARD MANDREL" SECRET OF TUBE-BENDING
ASSEMBLY OF MANDRELS WITH POPPET-STYLE LINKS
A DIFFERENT ANGLE ON WIPER DIES
Other Tech Info Links
LATEST TECHNICAL ARTICLE
4-STEP SET-UP PROCEDURE
MANDREL & WIPER CHARTS
FREE COPY OF
"THE ROTARY-DRAW TOOLING GUIDE"
OF THE LATEST BEND TOOLING TECHNICAL BULLETIN
Bend Tooling Inc. ~ 1009 Ottawa Avenue, N.W. ~ Grand Rapids, Michigan 49503,
TOLL-FREE (U.S.A. & Canada): 1-800-BTI-TUBE (1-800-284-8823) ~ WORLDWIDE:
REQUESTS FOR QUOTATION |
ORDER PLACEMENT |
© Bend Tooling Inc., 2006