Chasing the threads
Racer
Joined: Feb 2006
Posts: 269
Likes: 0
From: Vancouver B.C.
Whenever I chase a thread with a tap (of the correct SIZE) I've NEVER gotten any metal 'filings' in the debris, unless the thread was buggered first.
Forget this nonsense of a Tap vs. a Chase. All you want is to clean out the origonal threads of debris. A Tap made the First thread......use a Tap to CHASE the threads clean.
Sheesh!
Forget this nonsense of a Tap vs. a Chase. All you want is to clean out the origonal threads of debris. A Tap made the First thread......use a Tap to CHASE the threads clean.
Sheesh!
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
You really need clean threads to get accurate torque measurements, any junk in the thread COULD cause the torque reading to come up before the proper amount of clamping force is achieved. Most machinists measure the bolts for stretch whenever possible. IE: rod bolts. Torque is not really the best method for knowing when enough/proper clamping force is applied.
The idea of the thread chaser is jut to clean out old threads, A new tap COULD remove some metal? Don't forget everything has a tolerance, nothing is perfect. One hole in the block that does not hold torque is more costly than a set of thread chasers.
The idea of the thread chaser is jut to clean out old threads, A new tap COULD remove some metal? Don't forget everything has a tolerance, nothing is perfect. One hole in the block that does not hold torque is more costly than a set of thread chasers.
Racer
Joined: Sep 2007
Posts: 351
Likes: 1
From: Marysville OH
$50.00 at Sears for the set.
Every Sears store I have been in has them on the shelf.
The idiot employees won't have a clue WTF you want, but they are there in a red plastic case under the tap and die sets.
Craftsman 40 pc. Tap and Die Set, Master Rethreader
Sears item# 00952105000 Mfr. model# 52105
$49.99
http://www.sears.com/shc/s/p_10153_1...ord=rethreader
Every Sears store I have been in has them on the shelf.
The idiot employees won't have a clue WTF you want, but they are there in a red plastic case under the tap and die sets.
Craftsman 40 pc. Tap and Die Set, Master Rethreader
Sears item# 00952105000 Mfr. model# 52105
$49.99
http://www.sears.com/shc/s/p_10153_1...ord=rethreader
Pro
Joined: Oct 2004
Posts: 619
Likes: 1
From: Reno Nv
$50.00 at Sears for the set.
Every Sears store I have been in has them on the shelf.
The idiot employees won't have a clue WTF you want, but they are there in a red plastic case under the tap and die sets.
Craftsman 40 pc. Tap and Die Set, Master Rethreader
Sears item# 00952105000 Mfr. model# 52105
$49.99
http://www.sears.com/shc/s/p_10153_1...ord=rethreader
Every Sears store I have been in has them on the shelf.
The idiot employees won't have a clue WTF you want, but they are there in a red plastic case under the tap and die sets.
Craftsman 40 pc. Tap and Die Set, Master Rethreader
Sears item# 00952105000 Mfr. model# 52105
$49.99
http://www.sears.com/shc/s/p_10153_1...ord=rethreader
In some instances, these will will repair screwed up threads better than a tap or die. Sometimes they won't.
They're basically used for cleaning threads. If the threads are really messed up, throw away the bolt or helicoil the blind hole.
Thread Starter
Team Owner
Joined: Oct 2004
Posts: 35,065
Likes: 0
From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
If that were the case, why are chases even made?
BTW, I'm done. The threads were chased, then followed with a clean bolt before I bolted everything up.
Just wonderin' if there really is no need for a chase, why is the practice recommended by every engine builder I spoke to?
In fact, one went as far as to say "make sure it's a CHASE not a TAP".
BTW, I'm done. The threads were chased, then followed with a clean bolt before I bolted everything up.
Just wonderin' if there really is no need for a chase, why is the practice recommended by every engine builder I spoke to?
In fact, one went as far as to say "make sure it's a CHASE not a TAP".
Whenever I chase a thread with a tap (of the correct SIZE) I've NEVER gotten any metal 'filings' in the debris, unless the thread was buggered first.
Forget this nonsense of a Tap vs. a Chase. All you want is to clean out the origonal threads of debris. A Tap made the First thread......use a Tap to CHASE the threads clean.
Sheesh!
Forget this nonsense of a Tap vs. a Chase. All you want is to clean out the origonal threads of debris. A Tap made the First thread......use a Tap to CHASE the threads clean.
Sheesh!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
7 Bolt-On Upgrades From Extreme Online Store to Level Up Your C6 Corvette
Pouria Savadkouei
How Likely Are These Five 2027 Corvette Rumors to Be True?
Brett Foote
9 Best Corvettes You Can Buy for Half Price (& 1 You Should NEVER Buy!)
Joe Kucinski
8 Very Best Corvettes of Amelia Island 2026
Joe Kucinski
Top 10 WORST Corvette Engineering Failures of All Time!
Joe Kucinski
10 Records the C8 Corvette Generation Has SMASHED (& 1 Glaring Failure)
Joe Kucinski
7 Wildest Corvette Concepts Ever Made
Brett Foote
Racer
Joined: Feb 2006
Posts: 269
Likes: 0
From: Vancouver B.C.
Well?....
For the average guy, the whole CONCEPT of thread cleaning before a build is 'strange'.
Fact is.....cleaning the threads, if one is CAREFUL, can be done effectively with an inexpensive tap/die set.
Or have I wandered onto the Cessna Factory Mechanics Forum by mistake?
For the average guy, the whole CONCEPT of thread cleaning before a build is 'strange'.
Fact is.....cleaning the threads, if one is CAREFUL, can be done effectively with an inexpensive tap/die set.
Or have I wandered onto the Cessna Factory Mechanics Forum by mistake?
Last edited by Carpenter; Dec 14, 2007 at 09:21 PM.
Racer
Joined: Sep 2003
Posts: 275
Likes: 0
From: West Monroe La.
A tap can cut when used to clean threads. My machinist won't use taps to clean holes, and I wouldn't either. I have seen metal come out, even being "careful". Talk to a good engine builder and see what he says.
Thread Starter
Team Owner
Joined: Oct 2004
Posts: 35,065
Likes: 0
From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
But what do they know anyway? They're not on the interweb.
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
Yes, you are correct. Anything made with a milling machine can be made with a file. It takes a lot more time and a lot more expertise. If you have, and it seems you do, the hand skills then go for it. Using a chaser makes it a little safer for weekend mechanics.
Drifting
Joined: Oct 2006
Posts: 1,554
Likes: 13
From: Romeoville IL
Personally I would never use a tap to clean threads, a chase is the way to go. Cutting slots in the old bolts is a good second option.
On the note of helicoiling the hole. If you have damaged thread in something as important as a head bolt, go with a time-sert instead of a helicoil.
On the note of helicoiling the hole. If you have damaged thread in something as important as a head bolt, go with a time-sert instead of a helicoil.
Thread Starter
Team Owner
Joined: Oct 2004
Posts: 35,065
Likes: 0
From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
That's the way we used to do it, slot bolts across the threads on an angle.
Le Mans Master
Joined: Oct 2004
Posts: 5,841
Likes: 19
From: CLT, North Carolina
There are several different types of taps available and the most common are starting taps and bottom taps. If you are careful it is possible to chase threads with a bottom tap. The threaded holes were tapped with a tap to begin with so there is usually no difference in running a tap through the hole a second time. I say usually because there are some instances where there can be a concern. When threaded fasteners are tightened some elastic deformation does take place and with heat cycles and time it is possible the shape of the threaded hole has changed a small amount but this shape change would be very small. In this case it is possible some stock could be removed with a tap causing an increase in thread clearance affecting the fit but again the amount of stock removed is usually small. A starting tap is usually the most common tap to be found in the home toolbox but is a tapered tap and will not reach to the bottom of the threaded hole. If it were me I would play it safe and use a thread chaser. They are different in that they are a couple of thousandths smaller in diameter and do not have sharp edges which cut. You are just trying to clear the holes of debris and old sealants, etc.
Racer
Joined: Feb 2006
Posts: 269
Likes: 0
From: Vancouver B.C.
I apologize to anyone who was offended by my earlier posts. I certainly didn't intend to be 'pushy' or anything.....it's just that I personally found success using a cheapo tap/die set. Building my motor was a costly event for my budget, so I was always conscious of buying 'specialty tools' for something I may do once every two years or so. Wherever I could save a buck, while ensuring accuracy I DID. Everything I wrote was absolute truth (fussing the taps, ensuring no re-thread, finding no metal) so it was successful for ME.
Of COURSE engine builders want the absolute best tools for their builds! They must think about PRODUCTION. They have (and pay) techs that must be fast and efficient. If I had a pro production shop I'd insist in the best tools as well. Anything less would be sub-standard. But it's EASY for them to justify those tool costs....THEY DO HUNDREDS PER YEAR!
Again, I apologize to anyone I have offended.
Of COURSE engine builders want the absolute best tools for their builds! They must think about PRODUCTION. They have (and pay) techs that must be fast and efficient. If I had a pro production shop I'd insist in the best tools as well. Anything less would be sub-standard. But it's EASY for them to justify those tool costs....THEY DO HUNDREDS PER YEAR!
Again, I apologize to anyone I have offended.