How to inexpensively fix a stripped thread?

B

bluefitness

Member
I don't want to put too much into this old lawn mower. The threads stripped in one of the bolt holes for the intake. I don't have a tap and die set, but I can try to purchase one from Harbor Freight. I also read about Heli coil inserts. What is the least expensive way to repair this? Do you think it will hold if I just use RTV gasket and use a single bolt?
 
See what the next size up is in a metric bolt. Most hardware stores have individual metric taps and the bit needed together.
 
A few ways to fix it.
www.homedepot.com

E-Z LOK 1/4 in. to 20 in. x 1.5 in. D Coil Thread Repair Kit Economy EK20815 - The Home Depot

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Or go up to 5/16 self tapping screw
www.ebay.com

(4) 5/16"-18 Self Tapping Spindle Bolts used on craftsman & others | eBay

SELF TAPPING BOLT (SET OF 4). REPLACES EHP, AYP, HUSQVARNA, POULAN, CRAFTSMAN 138776, 157722, 173984. Quantity 1 = 4 bolts Quantity 2 = 8 bolts. 5/16" - 18 1" LENGTH. USED TO MOUNT AYP/EHP SPINDLES TO DECK.
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Or the poor man's route of grinding a slight taper on the end of the original bolt and put a couple of pieces of 16 or 18ga. Solid copper wire in the hole and crank the bolt in wedging the wires into the threads.
 
I noticed the threads came out (at least the top half of them did). Do they sell those self tapping screws locally?

What are your thoughts on this?
www.harborfreight.com

Carbon Steel SAE Tap and Die Set, 21 Piece

Amazing deals on this 21Pc Carbon Steel Sae Tap And Die Set at Harbor Freight. Quality tools & low prices.
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I'm guessing I would have to drill it out and tap it with the 5/16."
 
Forget the HFT tap and die sets. I purchased both a metric and SAE sets. They were so poorly made I return them as soon as opened them up.
 
bluefitness said:
I noticed the threads came out (at least the top half of them did). Do they sell those self tapping screws locally?

What are your thoughts on this?
www.harborfreight.com

Carbon Steel SAE Tap and Die Set, 21 Piece

Amazing deals on this 21Pc Carbon Steel Sae Tap And Die Set at Harbor Freight. Quality tools & low prices.
www.harborfreight.com www.harborfreight.com

I'm guessing I would have to drill it out and tap it with the 5/16."
Click to expand...
A good hardware store should have them. Go up to whatever is just bigger than what you have be it SAE or metric and you should be able to cut in new threads without drilling.
 
Sets are waste of time and carbon steel ones ever a bigger waste of time , money & the resources of the planet
To do what you want you will need either a second tap & a bottom tap so there will be no threads down the bottom of the hole .
Extreme care is needed as the holes run close to the hole for the air:fuel supply and if you drill into that you are in for an expensive repair using solid air tight inserts .
The copper wire usually works if there is sufficient thread root to anchor the copper wire.
You might need to do it a dozen times before you get enough in there to hold as you have to do it a little at a time.
This was a common repair to motorcycle magneto points, where the steel thread went into the zinc arm .
Lots of goos , make a thread etc that do work IF YOU READ & FOLLOW THE INSTRUCTIONS which sems to be beyond the mental capacity of 99.9 % of the people who use it.
 
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