M8x1 to m8x1.25

[gary55]

That would be a b**ch to get everything prepared and purchased then blow the case out. I would definitely err on the side of caution and use a tap on this one. The only thread repair I have done is the helicoil. So far they have all worked very well. That includes numerous head studs. Some say it's a stronger connection than the original. I believe it. At least when used in aluminum.

 

[willis617]

That would be a b*tch to get everything prepared and purchased then blow the case out. I would definitely err on the side of caution and use a tap on this one. The only thread repair I have done is the helicoil. So far they have all worked very well. That includes numerous head studs. Some say it's a stronger connection than the original. I believe it. At least when used in aluminum.

A helicoil is stronger because the coil has a larger diameter and more circumference, more contact area with the base metal than what it replaced, then fastener and thread are steel on steel

 

[gary55]

That's what I figured. That it would be stronger when used in any material that was weaker than the coil or the fastener.

 

[Spare_Parts]

Not a fan of the spring type at all. If I have the tap and 7mm from center of hole to the edge of the case I'll use ez-lok. If not either of those it will be tap-lok because they are 11.2mm od and self tapping.

As far as metric course vs fine here is a chart.

Basic Metric Thread Chart (M1 - M100)

Fuller Fasteners, Distributor of Metric and Imperial Fasteners, stainless steel, brass, nylon, hex nuts, bolts, nuts, screws, taps, dies, tools and kn95 masks

www.fullerfasteners.com

 

[willis617]

Not a fan of the spring type at all. If I have the tap and 7mm from center of hole to the edge of the case I'll use ez-lok. If not either of those it will be tap-lok because they are 11.2mm od and self tapping.

As far as metric course vs fine here is a chart.

Basic Metric Thread Chart (M1 - M100)

Fuller Fasteners, Distributor of Metric and Imperial Fasteners, stainless steel, brass, nylon, hex nuts, bolts, nuts, screws, taps, dies, tools and kn95 masks

www.fullerfasteners.com

I get that 1.25mm is classified as "corse", and 1.0mm is "fine"
My point was there is only a .010 inch difference in pitch, and both exceed 20 threads per inch