Having trouble with breaking lifter rods.Using .5oo diameter Thompson Shaft-grinding to .437 diameter for about 3/4"-pinning with 3/16 coil pin.Any ideas?

Thompson shafting is commonly used in lifter rod applications but be advised that it is only 'case' hardened on the OD with a soft core ( this makes it convenient to drill/tap etc.)so by grinding down to .437 you are into the soft core ( not much strength ). The material is typically 52100 bearing steel which is ideal for the roller bushings that are used with this product but I feel other materials would be better suited for a lifter rod application. I'm not clear where it is breaking. If you call me or E-mail me so we can discuss this more in detail I would be more than happy to try to help. Thanks in advance. Mike Biddle Sr. Product Specialist P.C.S. Co. 1-800-521-0546

Try using ejector pin. It is thru hard which will give you extra strength. It is a little harder to drill and tap, but it can be done.