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10A
Jackbar Assembly (Chart 8)
10A.1.1 Check the surface of the Jackbars (Chart 8 item A1) with a straight edge (item “A” of required equipment list) to
determine if the Jackbars is bent. The surfaces to check are:
a. The surface “A” of the Jackbars that makes contact with the pipe.
b. The surface “B” into which the jackscrew(s) (A3) fit.
10A.1.2 Check the threaded hole into which the Thumbscrew (Chart 13 item A4) and Jackscrew (Chart 13 item A3) fit for
loose threads, galled or missing threads.
10A.1.3 Screw the appropriate Thread Gauge from the equipment required list) into the threaded hole for Thumbscrew
(Chart 13 item A4) and Jackscrew (Chart 13 item A3). If play exceeds .010 thousands of an inch of play between the
thread gauge and threaded hole of the Jackbar replace the Jackbar.
NOTE:
Mathey Dearman Inc. will not warrant or accept any responsibility for heating, welding and straightening of
New Style Cast Jackbars or Old Style Jackbars.
10A.2 Chain Lock (Chart 8 item A2)
10A.2.1 The Jackbars (Chart 8 item A1) must have a Chain Lock to function properly and avoid damaging the chain. If the
Chain Lock is missing, install a new Chain Lock before using the clamp
10A.2.1 Check the Chain Lock to make sure the points of the Chain Lock that contact the chain are not worn through. If the
Chain Lock is worn through, replace the Chain Lock.
10A.3 Jackscrew (Chart 8 item A3)
10A.3.1 The Jackscrew should never be used without the stainless steel swivel pad. If the swivel
pad is missing replace the Jackscrew.
10A.3.2 Check the Jackscrew to make sure the tip, that contacts the pipe, will
rotate freely without binding. If the tip will not rotate or is difficult to turn it will mar the
pipe. If marring of the pipe or pipe coating is a concern, replace the Jackscrew.
10A.3.3 Check threads of the Jackscrew for galled or missing threads. If the threads are galled or
missing threads, replace the Jackscrew.
10A.3.4 Screw the Jackscrew into the Jackbars (Chart 8 item A-1). If play
Between Jackscrew and Jackbars (Chart 8 item A1) exceeds .010 of an inch, perform
repair step 11A.3. If testing in repair step 11A.3 is within tolerance, replace the Jackscrew.
If testing in 11A.3 proves the Jackbars threads are out of tolerance, replace the Jackbars.
10A.3.5 Check the Jackscrew for straightness. A Bent Jackscrew will not function properly and
should never be used. If it is bent, replace the Jackscrew.
WARNING:
To insure the safety of the operator all bent Jackbars should be replaced or
tested with some means of nondestructive testing to determine if there are cracks prior to
any further use. Jackbars with cracks should not be used under any circumstance.
WARNING:
To insure the safety of the operator, the Jackbar (Chart 8 item A1) should be
replaced, if threaded holes for the Thumbscrew (Chart 8 item A4) or Jackscrew (Chart
8 item A3) have loose, galled or missing thread.
WARNING:
H
eating, welding and straightening of New Style Cast Jackbars or Old Style
Jackbars may cause failure of the Jackbar result in injury to the operator.
