Thread repair inserts

[Tohya]

I like the idea of retapping the M5. What was the PN on the solid insert? The link doesn't work?

Thanks for bearing with me guys. I just went and checked, and was able to tap them out to 1/4-20. Guess I was making this harder than it needed to be. Thanks for the good ideas though.

The Solid insert are on page 420 of the MSC Big Book. http://www1.mscdirect.com

The inserts are
MSC #: 04253894 Carbon steel
MSC #: 82498023 Stainless steel

 

[srcarr52]

Fine.

http://www.mcmaster.com/#threaded-inserts/=9xsq0o

They have 10-24 inserts with locking pins.

 

[Beowulf]

I've used a lot of H-coils when I was working in the tool room at the thermoforming Co. They lasted many of "in and outs" of the bolts. That's a lot more wear and tear the saw bolts are going to see.

Nothing wrong with H-coils. They are stronger than the orginal thread. How much stronger does one need?

Kinda for what it's worth; there are an awful lot of heli-coils flying in military aerospace applications as original design/installation. The key is good application technique, including locking them in place with a red loctite type permanent compound. I've never been afraid to use them in motorcycle applications, as long as there was enough metal to cleanly tap for their installation.

 

[srcarr52]

Kinda for what it's worth; there are an awful lot of heli-coils flying in military aerospace applications as original design/installation. The key is good application technique, including locking them in place with a red loctite type permanent compound. I've never been afraid to use them in motorcycle applications, as long as there was enough metal to cleanly tap for their installation.

A lot of after market aluminum heads for racing applications (SBC, SB2, LS) come with them pre-installed for the exhaust bolt holes. Sometime they put them in the intake bolt holes as well.

 

[Cliff R]

Heli-coil inserts are fine, and as mentioned much stronger than the original material.

You also have the option to shorten them up for holes without sufficient depth to accept all the threads, or double them up for deeper holes for more threads.

I install them daily in our shop as we retore thousands of old carburetors, many will require heli-coils at one or more places due to the age of the material and thread errosion, etc.

Just a note on heli-coil installation in soft materials. In most cases it is NOT necessary to drill the material. If the threads are stripped out, pulled out, missing, etc, the existing hole is usually large enough to start the heli coil tap. It's pretty easy to "hog" out the hole when drilling them unless the base material is clamped down and a drill press is used.

Use PLENTY of lubricant when tapping the new hole. I use clean ATF here as it's just easier to obtain than cutting oil. Make sure the heli-coil insert is at least one half to one full thread below the surface, or it can bind up and split the base material.

For most chainsaw stuff, I tap/heli-coil to 10-32, as we stock black oxide coated fasterners in Fillister heads, and Pan heads in that size in lengths to 3". The 10-32's are also almost exactly the same as the metric screws used on most Husqvarna saws to retain the starter cover and many other items......Cliff

 

[leeha]

Brad,

Just use helicoil's. You can put red locktight on it if you are afraid of it backing out on the screw.

Look on amazon for the best price on helicoil kits.

What do you have against using the helicoil.

Iv'e been using Helicoils for the better part of 35
years and never had a problem. Alot stronger than
the original thread and you don't make a huge hole
like with the other inserts.


Lee

 

[rg50]

As a machinist,I have installed thousands of Helicoils in the aerospace parts we have made at my shop.
If the FAA approves them for flight,they should be good in a saw.

 

[Tzed250]

.


This is a Heli-Coil product, but it is solid:


insert by zweitakt250, on Flickr


.

 

[parrisw]

Just how strong is Heli-coil rated? I once had to repair all the rocker arm stud threads in a Chevy V6, aluminum heads, and it was not recommended to use heli coils? So I used Keenserts.

 

[1steve]

Just how strong is Heli-coil rated? I once had to repair all the rocker arm stud threads in a Chevy V6, aluminum heads, and it was not recommended to use heli coils? So I used Keenserts.

Standard type helicoil has a tensile strength of 200,000-250,000 psi, as for helicoils not being recommended that would be a first for me. Who's didn't recommend them? There are some aluminum heads that come from factory with helicoils already installed........just stronger IMHO

 

[parrisw]

Standard type helicoil has a tensile strength of 200,000-250,000 psi, as for helicoils not being recommended that would be a first for me. Who's didn't recommend them? There are some aluminum heads that come from factory with helicoils already installed........just stronger IMHO

Machine shop.