Tom hadlow
Active OPE Member
I am needing to helicoil a Ms150t cranks case mount and the bolt isA IS-D5x26 does any one know what the helicoil would be needed for this
Can any one tell me what type of thread this is
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Tom hadlow
Active OPE Member
Hi mate this is a picture of the bolt that I need to helicoli it is the same diameter as an m5 but has a coarser thread
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Tom hadlow
Active OPE Member
Hi mate thank for you help what would I have to look up the find the right helicoil kit
Thanks Tom
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That is a thread cutting screw. You won’t find a repair kit for it. The hole would be about right for an M5 helicoil kit. (or thread sert) Replace it with a machine screw.
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I see now the thread is kinda old. He prolly figured it out. 
legdelimber
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That image looks like one of those "tri-lobe" threaded screws.
They work by displacing the material as you turn them into the hole. The material gets packed into the flat(ish) areas of the threaded diameter and -sort- of hold the screws in then.
Look from the tip end think of something like the shape of the Wankel engine rotor.
Look at the threads on the screw and notice the three regions with crud packed into them and then the 3 high spots between them.
Trouble is the displaced material eventually compacts and then the fasteners become loose and rattle out.
This material displacement method also leaves a semi-stripped hole even upon the initial installation of the fastener.
That's why we see so many conversations regarding striped holes, caused by these Tri-Lobe fasteners.
I'll have to see if I can get a couple of decent photos of the tri-lobes again.
They work by displacing the material as you turn them into the hole. The material gets packed into the flat(ish) areas of the threaded diameter and -sort- of hold the screws in then.
Look from the tip end think of something like the shape of the Wankel engine rotor.
Look at the threads on the screw and notice the three regions with crud packed into them and then the 3 high spots between them.
Trouble is the displaced material eventually compacts and then the fasteners become loose and rattle out.
This material displacement method also leaves a semi-stripped hole even upon the initial installation of the fastener.
That's why we see so many conversations regarding striped holes, caused by these Tri-Lobe fasteners.
I'll have to see if I can get a couple of decent photos of the tri-lobes again.
