I need to repair a few threads on this old Homelite 1050 I'm working on. The threads are 12-24. I can't find keysert style inserts in that size. Anyone have any tips?
Thread repair inserts
- Thread starter blsnelling
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Saw Dr.
Junk Collector
Folks around here seem to think drywall screws are OK. Just found one wound into the case on an upper 044 mount today. Very nice saw. That made me very sad.
54stude
ArboristSite Operative
Are the inserts structural?
If not, could you use 10-24 or 10-32 threaded inserts?
If not, could you use 10-24 or 10-32 threaded inserts?
stihlboy
Guess who's back
Cant help with any tips but will comment on the 12-24 thread size. Very common in the glass and glazing industry. Just about every hinge screw with a machine thread is that size. If you need some countersunk type heads, let me know, might be able to find a few pan heads also. If you have room for an insert can you just drill and tap next size up-1/4-20 or 1/4-28? REJ2
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I'd prefer not to use Helicoil type inserts, but I'm sure they'd work fine. the offending bolts are the three that bolt the recoil to the flywheel housing. I'm going to see if I can upsize them to 1/4-20.
stihlboy
Guess who's back
54stude
ArboristSite Operative
If you used 10-24 or 10-32 inserts in this application, each of them would provide 700-800 lbs of clamping load in this application. This is likely a place where overkill is not necessary, as long as you only apply 2-3 ft-lbs of torque to the fastener upon assembly. Take a look at this table to see how much clamping load fasteners apply.
http://www.spaenaur.com/pdf/sectionD/D48.pdf
A metric M5 fastener is really really close to a 10-32 fastener. You can interchange the nuts in some cases, they are that close. M5's are used all over new Stihls, even the cylinder bolts on a bunch of the saws.
http://www.spaenaur.com/pdf/sectionD/D48.pdf
A metric M5 fastener is really really close to a 10-32 fastener. You can interchange the nuts in some cases, they are that close. M5's are used all over new Stihls, even the cylinder bolts on a bunch of the saws.
The only catch with those is that they're "countersunk". For keyserts I've used before from MSC, you simply drill and tap the hole, thread the insert to where you want it, and then top the locking pins down on the sides. No special installation tools are required, besides a drill and tap. They just don't come in 12-24
These are #12. How about going with 6mm then? I actually have a couple 6mm keyserts here. Hmmm.
Great
You can't get metric Slotted Hex Washer Head Machine Screws. Maybe I'll just stick with the 1/4-20 idea.54stude
ArboristSite Operative
The nice thing about using a #10 is you would not have to drill it as much oversize to start, leaving yourself some room in case one fails.
You could rethread a M4 or maybe M5 insert to 12-24.
Here is a 5/16" solid insert.
The M4 and M5 insert uses a 8mm tap, close to 5/16", the M6 insert use a 10mm or 12mm tap.
Here is a 5/16" solid insert.
The M4 and M5 insert uses a 8mm tap, close to 5/16", the M6 insert use a 10mm or 12mm tap.
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parrisw
Tree Freak
Easy, get Nik to make you a few in the machine shop! I made some for a 395, and just used permanent loctite, they are still holding great.
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.
srcarr52
We can't stop here, this is bat country.
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.
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.
They're fine, but solid inserts are better.
parrisw
Tree Freak
:agree2::agree2:
Dan_IN_MN
Addicted to ArboristSite
How much stronger does one need?
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?
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?
