Discussion and questions related to the course EFI Wiring Fundamentals
While stamped & formed open barrel design pins are cheaper, how are they not better since they have the tangs for crimping around the insulation? Solid closed barrel pins do not have this, so doesn’t the insulator simply bump up tight to the collar of the pin?
Which is the most durable and provides the best stress relief? If it is the open barrel, then why are the considered the economical / cheap version of pins?
Closed barrel pins, when crimped using the correct size wire will provide a higher tensile force rating when crimped correctly. The strain relief comes by stripping extra insulation off the wire, approximately 1 wire diameter size or smaller. Do not insert the wire so that the insulation is in contact wire the collar of the terminal as this could lead to failure due to not having any flexibility behind the joint. In most applications where strain relief is a big factor, another method like service loops are used to add the extra strain relief. Having a stronger crimped joint is more important as strain relief can be added later to the application like using the aforementioned service loops.
Excellent reply. Thank you.
I dont recognise the connectors shown in the pics above so dont have any specific experience with them, but I will add a comment to Brandons reply;
Most connectors that use solid (closed barrel) terminals have strain relieve built in as part of the design, the wire will usually pass through some form of rubber seal behind the terminal that grips around the insulation. Look at a DTM connector as an example. In many cases in motorsport applications they would be booted for further strain relieve also.
I don't think most people realize that strain relief isn't really meant to add rigidity or tensile strength but to spread the area that gets loaded to avoid work hardening and ultimately fracturing.