BEND TOOLING INC.:  Rotary-Draw Tube-Bending Tools ~ Die Sets ~ Mandrels ~ Wipers ~ Mandrel-Bending Tools

Tech Article #607

Home | Technical Information | Current Technical Article

See sidebar for links to other tech articles.


Poppet Links vs. Split Links

(one-piece links vs. multi-piece links)

by 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 link.

 

These are the advantages of Bend Tooling’s poppet link over the split link:

 

bullet

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.

bullet

 The 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 fracture.

bullet

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 links.

bullet

Because of these three factors, the poppet link has a longer life than the split link.

bullet

Because the poppet link is simpler in design, it requires less time to manufacture.  Therefore, the poppet link is considerably less expensive than the split link.

bullet

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.

bullet

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.

bullet

Finally, the 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 Links".

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

ENCYCLOPEDIA INTRO

   VOLUME A-B

   VOLUME C-D

   VOLUME E-K

   VOLUME L-N

   VOLUME O-Q

   VOLUME R-S

   VOLUME T-Z


LATEST TECHNICAL ARTICLE

4-STEP SET-UP PROCEDURE

TROUBLESHOOTING

BENDING FORMULAS

CONVERSION FORMULAS

GEOMETRIC FORMULAS

MANDREL & WIPER CHARTS


FREE COPY OF "THE ROTARY-DRAW TOOLING GUIDE"

FREE COPY OF THE LATEST BEND TOOLING TECHNICAL BULLETIN

PRODUCT INFORMATION


MAIL TO: Bend Tooling Inc. ~ 1009 Ottawa Avenue, N.W. ~ Grand Rapids, Michigan 49503, U.S.A.

TOLL-FREE (U.S.A. & Canada): 1-800-BTI-TUBE (1-800-284-8823) ~ WORLDWIDE: 616-454-9965

FAX: 616-454-9958 ~ E-MAIL: info@bendtooling.com

INQUIRIES | REQUESTS FOR QUOTATION | ORDER PLACEMENT | CUSTOMER SERVICE

© Bend Tooling Inc., 2006