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Username Post: Tapped main bolt threads on new block... What to do?        (Topic#361563)
Chevytu 
Senior Member
Posts: 248
Chevytu
Loc: Argentina
Reg: 12-29-02
06-29-20 01:59 PM - Post#2797457    

After lots of issues with an old Mark IV I decided to sell it and bought a new Dart Big M BBC.

Had it completely machined and when picked up asked if everything went fine. Guy told me "we ran a tap on 3 main holes as the bolts were hard to turn giving incorrect torque readings.." I cringed... No chaser, a regular tap.

Finally took the block home after arguing and getting nowhere.. Whats done it's done I guess. Left it there for a while.

Last week bolted all mains up with the stock Dart bolts. Torqued up to 100 using darts lubricant. All OK, nothing felt funny and held up just fine.

Had a set of new ARP studs and installed those. Again torqued up in 3 steps to 110 as per ARPs instructions. All OK. Also clearances did not change at all with the studs, so will use these for piece of mind.

Returned to the shop, much to my regret, and got the taps dia measured. They are 0.012" larger than the studs dia.

Also measured the "side to side play" of the studs (without the main saddles on of course). Screwed them up all the way and then backed 1 turn. Measured as close to the main surface as possible. All of them move 0.0015" to 0.0025". The ones these ppl redid (the outer on the 3rd cap and the inners on 4th and 5th cap), have 0.003 to 0.004" side play (they of course felt "looser" just by feeling while screwing them on...

Now my question is: Should I leave as it is or fix it? I know the studs are clamping as they should, but once you spin a 75 lb crank to 6.000 or 7.000 rpm there will be a lot of punding down there, isn't it? So clamping force is one thing but I suppose the mains have to endure the extra forces a running engine will have... For (crossed fngers) a long time... This is not a race engine that will get torn down every weekend to check on things.

I have access to a nice large mill. Was thinking of drilling these threads out and inserting 1.25" helicoils tightly in place.. Am I overthinking this? So afraid to break up something I will never be able to afford again that I'm getting paranoid.

Sorry for the long post.. any opinions appreciated. If there's another way to check these holes please let me know.

Thanks

1966 Chevy II SS, BBC


 




grumpyvette 
Senior Chevytalk Moderator -- Performance Subject Matter Expert --
Posts: 17510
grumpyvette
Age: 72
Loc: FLORIDA USA
Reg: 03-16-01
06-29-20 06:33 PM - Post#2797481    
    In response to Chevytu

well my first thought was why not call and talk to dart and ARP as it is their block and their studs.
but I've used several DART big M blocks and dozens of sets of ARP main cap studs , and honestly, I don,t think your running any risk.

https://www.jegs.com/p/Dart/Dart-Big-Block -Chevy-B...

https://www.competitionproducts.com/Dart-Big-M-Mac...

https://rehermorrison.com/product/bbc-blocks/

https://www.summitracing.com/search?SortBy=BestKey ...


https://arp-bolts.com/kits/product.php?PL=29&S...

https://arp-bolts.com/kits/make.php?_Make=301&...

https://www.amazon.com/UNC-Thread-Chaser-Ret hreadi...




IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!


 
Rick_L 
Member #409
Posts: 27733
Rick_L
Loc: Katy, Tx, USA
Reg: 07-06-00
06-29-20 07:57 PM - Post#2797489    
    In response to grumpyvette

  • Quote:
I know the studs are clamping as they should, but once you spin a 75 lb crank to 6.000 or 7.000 rpm there will be a lot of punding down there, isn't it? So clamping force is one thing but I suppose the mains have to endure the extra forces a running engine will have...



Clamping force is what lets the block/mains endure all those "extra forces".

I would definitely get a comment from Dart before putting helicoils in those holes. Drilling and tapping for a helicoil is going to make the wall thickness from the hole to the outside edge thinner. I doubt if that's a problem either but it doesn't hurt to ask.



 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
06-30-20 07:53 AM - Post#2797524    
    In response to Chevytu

I'm sorry, I am going to be the devil's advocate here on this.

I know for a fact after working for GM and other manufacturers, that a CUT thread tap, or chaser is NOT the cutter/cleaner to use in a ROLL thread hole, as the cut thread removes the end areas of the threads in the material from a roll strong end, to a sharp, weakened end thread, weakening the threads.

Those threads may well hold for a while, or cold, but what will occur when the fasteners get to optimum stretch, vibration, AND heat levels?

I may be wrong on that particular block, but if it were mine, two things would happen with it, the "machine shop" wouldn't ever machine anything for me again, and, it would become a destroyed table support for my front room.

I would also have been very suspect of the three threads in the first place.



 
Chevytu 
Senior Member
Posts: 248
Chevytu
Loc: Argentina
Reg: 12-29-02
06-30-20 05:39 PM - Post#2797581    
    In response to IgnitionMan

Thanks for the replies.

I was getting some piece of mind before this final post... :sad : but better to get as much information as possible based on your experiences.

Of course I will never set foot on that shop again, just can't believe they would do that, at least they should have told me before.

No matter what I will have to either build it like this or helicoil it, there is no way I can get another block sent. I live overseas and with the pandemic and the economy taking a huge fall it is impossible now, and will be for quite some time (maybe years... The USD has quadrupled in price since I bought it and it continues to climb, even daily).

I understand your last explanation about how the threads are rolled in the block. It is a fact these have weakened, just can't check by how much, that is why I was going for the helicoils. The block itself looks like a tank, a lot beefier than the stock Mark IV, so I don't think a helicoil could mess it up, it takes very little material. I thought it could be the only solution. Had some head bolt holes repaired like this on a stock GM block and they worked perfectly. Of course they were rusted out so it was either that or throwing the block to the thrash..

I will send Dart an email and see what they tell me (if they respond, sent them an email when I bought the block to ask for correct cam bearing position and p/n and they never got back to me).

1966 Chevy II SS, BBC


Edited by Chevytu on 06-30-20 05:43 PM. Reason for edit: No reason given.

 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
07-01-20 01:22 PM - Post#2797654    
    In response to Chevytu

I have to add that myself, I would NEVER Heli-Coil a main, or head bolt hole, they are just not worth it, nor strong in those situations.

I would ask DART if a larger stud/bolt could be used in place of the ones initially tapped, and, would they might make a stepped thread stud for that sort of application?

Tierra del Fuego, We always thought there should be some sort of combined Grands Prix and Easter Egg Hunt there, for our motorcycle road races.



 
Chevytu 
Senior Member
Posts: 248
Chevytu
Loc: Argentina
Reg: 12-29-02
07-01-20 05:06 PM - Post#2797670    
    In response to IgnitionMan

Well... Lots of strange things happen down here, but I have yet to see something like that!

Got an email from Dart, and of course they tell me it should be checked at the factory or replaced... Not going to happen soon I'm afraid.

Helicoils are made of case hardened stainless steel, my belief is that is a lot stronger than brittle cast or even nodular iron... Just checked they are 220.000 psi (?)

I got in contact with a well known race shop up north that does racing engines for a popular road race series here. These are all destroked classic Chev, Ford, and Dodge straight sixes. The Chevrolet motors spin to 9.500 rpm and crank around 350 hp with a restrictor plate. Races last for about 1 to 2 hours. They told me they helicoil them all the time as these blocks are extremelly old 2-bolt main gray iron and with all the crank whip they take a big toll... I know, different scenario as once the race is over practically the whole thing gets replaced, but still that's a lot to endure.

Since there is not much I can do, I will try this route on a practice SBC I have that is not salvageable and see how they work. Also seen the time-serts that are available in stainless now, as opposed to the original carbon steel sets that I believe are around Grade 5... Not even close for this kind of repair.

A stepped stud also sounds like a great solution but I don't believe they or ARP would special make 3 studs, or even certify that as a repair. I could be wrong, doesn't hurt to ask. Have not seen something like this offered anywhere that I can think of.

Thanks for all the help, much appreciated.

1966 Chevy II SS, BBC


 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
07-01-20 05:16 PM - Post#2797673    
    In response to Chevytu

The Heli-Coil is the weakest of thread inserts, they are subject to racking in the threads, which is, pulling opposed threads to different sides of the threading, load axis to load axis.

I use a good quality thread insert, one that is a full piece, not a coiled piece of metal, they just work better in everything I ever had to fix a thread in.

I do hope whatever you do works great, sir.



 
Chevytu 
Senior Member
Posts: 248
Chevytu
Loc: Argentina
Reg: 12-29-02
07-01-20 05:48 PM - Post#2797675    
    In response to IgnitionMan

Thanks for the info

By just looking at the design I would assume that a solid insert would be the strongest, but of course looks is one thing... Plus I know nothing on thread repair.

I believe a stainless time sert would be the best, but I don't think they are available here. In any case I might order a set later on when we get out of this Covid pandemic, as all regular flights are cancelled thus there is no international mail at the moment.

Thank you again for your time, I dearly hope something works out..

1966 Chevy II SS, BBC


 
CNC BLOCKS N/E 
Senior Member
Posts: 983

Loc: NORTH EAST
Reg: 12-12-03
07-05-20 07:45 AM - Post#2797954    
    In response to Chevytu

  • Chevytu Said:
After lots of issues with an old Mark IV I decided to sell it and bought a new Dart Big M BBC.

Had it completely machined and when picked up asked if everything went fine. Guy told me "we ran a tap on 3 main holes as the bolts were hard to turn giving incorrect torque readings.." I cringed... No chaser, a regular tap.

Finally took the block home after arguing and getting nowhere.. Whats done it's done I guess. Left it there for a while.

Last week bolted all mains up with the stock Dart bolts. Torqued up to 100 using darts lubricant. All OK, nothing felt funny and held up just fine.

Had a set of new ARP studs and installed those. Again torqued up in 3 steps to 110 as per ARPs instructions. All OK. Also clearances did not change at all with the studs, so will use these for piece of mind.

Returned to the shop, much to my regret, and got the taps dia measured. They are 0.012" larger than the studs dia.

Also measured the "side to side play" of the studs (without the main saddles on of course). Screwed them up all the way and then backed 1 turn. Measured as close to the main surface as possible. All of them move 0.0015" to 0.0025". The ones these ppl redid (the outer on the 3rd cap and the inners on 4th and 5th cap), have 0.003 to 0.004" side play (they of course felt "looser" just by feeling while screwing them on...

Now my question is: Should I leave as it is or fix it? I know the studs are clamping as they should, but once you spin a 75 lb crank to 6.000 or 7.000 rpm there will be a lot of punding down there, isn't it? So clamping force is one thing but I suppose the mains have to endure the extra forces a running engine will have... For (crossed fngers) a long time... This is not a race engine that will get torn down every weekend to check on things.

I have access to a nice large mill. Was thinking of drilling these threads out and inserting 1.25" helicoils tightly in place.. Am I overthinking this? So afraid to break up something I will never be able to afford again that I'm getting paranoid.

Sorry for the long post.. any opinions appreciated. If there's another way to check these holes please let me know.

Thanks



I machine and sell a lot of Dart blocks and to date never had any issues with the bolt holes in the decks or mains. When the mains are tapped at Dart its the same tap for all 20 holes, I would say the shop messed something up and is trying to blame Dart.

Going to studs often changes the housing bore size and should be addressed with an align hone.




Edited by CNC BLOCKS N/E on 07-05-20 07:45 AM. Reason for edit: No reason given.

 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
07-05-20 08:56 AM - Post#2797964    
    In response to CNC BLOCKS N/E

CNC, it ISN'T that the bolt holes were tapped to clean them, the key issue is thread strength after the wrong thread design tap was used to do that operation at a machine shop long after DART built the block.

At least, that is what I am getting from all of it, so far.



 
Chevytu 
Senior Member
Posts: 248
Chevytu
Loc: Argentina
Reg: 12-29-02
07-06-20 05:14 PM - Post#2798069    
    In response to IgnitionMan

Yes that is correct.

Nothing to do with Dart I guess. There seemed to be a resistance on these 3 bolts and they "cleaned" the threads by running a regular 1/2"-13 Tap. That is all. Not sure why these holes were having that issue, maybe they were to spec anyways but the shop figured otherwise... :sad :

FWIW I did torque all mains down (100 ft/lbs, as stated on Darts spec sheet) using the bolts supplied with the block (using their thread lubricant). Then switched to ARP studs, and again torqued all up (110 ft/lbs as per their sheet) with the ARP fastener grease. Measured all mains before and after, with no change or distortion. The block is massive, so maybe it doesn't move as much as a stock GM.

My concern is, as Ignitionman stated, that by running the tap to clear the holes they are now weaker to the point that a failure might occur later on.

Thanks

1966 Chevy II SS, BBC


 
grumpyvette 
Senior Chevytalk Moderator -- Performance Subject Matter Expert --
Posts: 17510
grumpyvette
Age: 72
Loc: FLORIDA USA
Reg: 03-16-01
07-06-20 05:41 PM - Post#2798073    
    In response to Chevytu


next time the main cap bolts seem tight throw an ounce of diesel fuel in the threaded hole and use a drill with a 50 cal brass brush to clear crud from the threads before doing anything else
then blow out the loose crud and solvent with high pressure air


IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!


Edited by grumpyvette on 07-06-20 05:47 PM. Reason for edit: No reason given.

 
Chevytu 
Senior Member
Posts: 248
Chevytu
Loc: Argentina
Reg: 12-29-02
07-07-20 01:55 PM - Post#2798162    
    In response to grumpyvette

Thank you for the info
Yes I have a complete set of brushes, both plastic and wire.
Did not clean the block before sending it as I would have to do it all over again afterwards. Should've done it before also..

1966 Chevy II SS, BBC


 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
07-07-20 03:52 PM - Post#2798171    
    In response to Chevytu

I am still very concerned of what is possible after the engine is put back into service and encounters the forces, vibration and heating cycles it does as it runs.

Possibly, and I hope this is the way it goes, nothing bad will occur. But, there is always any scenario that can develop.

My sincere hope is it all works out for the good.

Now, as far as the Grands Prix, and Easter Egg Hunt........



 
Rick_L 
Member #409
Posts: 27733
Rick_L
Loc: Katy, Tx, USA
Reg: 07-06-00
07-07-20 04:35 PM - Post#2798174    
    In response to IgnitionMan

Just askin' here, I don't think anyone who replied so far knows - but is there any assurance that Dart used rolled threads? Seems they could have used a conventional tap.

I know the GM factory is reputed to use rolled threads, but aftermarket blocks?

That said, one should use a "chaser" tap in a thread already tapped.



 
Chevytu 
Senior Member
Posts: 248
Chevytu
Loc: Argentina
Reg: 12-29-02
07-07-20 06:33 PM - Post#2798177    
    In response to Rick_L

My understanding is that rolled threads can be put on fasteners, but not on a hole, as it involves 2 big rollers that "squeeze" the threads out of the material to form them. I presume that is impossible to do on a hole. Threads I'm sure are cut, but clearances and other details can be different depending on use I guess.

I did buy a set of regular 1/2" taps and they will not go into the stock Dart holes (just tried by hand of course...), but they will fit the 3 holes, so there's definetely more clearance there, or a slightly different finished shape as Ignitionman mentioned, thus they are weaker that's for sure. These also are .012" larger in dia. (than the studs, not the threads on the block).

I also got to talk over the phone with a local (as in this country, of course not my city) B

1966 Chevy II SS, BBC


 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
07-08-20 09:30 AM - Post#2798215    
    In response to Chevytu

Actually, roll threads came into being before engines, for mining pumps and other high pressure pumps.

I don't know of any main, head and other engine threads that were NOT roll threaded, no matter the block material.

Just what I have known to be accurate since I was 9 years old, and worked on my first engine with my dad, it was a Flat Head "Bent Henry".



 
65_Impala 
Very Senior Member
Posts: 4491

Reg: 12-29-02
07-08-20 09:47 AM - Post#2798216    
    In response to Chevytu

  • Chevytu Said:
My understanding is that rolled threads can be put on fasteners, but not on a hole, as it involves 2 big rollers that "squeeze" the threads out of the material to form them. I presume that is impossible to do on a hole. Threads I'm sure are cut, but clearances and other details can be different depending on use I guess.




You are correct about rolled threads only being possible on external threads, but both internal and external threads can be created using a thread forming technique. Creating internal threads is call thread forming and uses a thread forming tap.

Rolling threads save manufacturing money. Making fasteners using rolling dies is a big savings vs cutting because the factory can create the whole thread length at once as they roll the blanks through the dies. They can feed multiple blanks into the dies one right after the other. The blank is also thinner so it saves in material cost.



 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
07-09-20 12:36 PM - Post#2798282    
    In response to IgnitionMan

When will 65_Impala stop misleading people? These are the TAPS that are used to create a roll type thread in aluminum and other metals by deforming the base metal into a thread.

mcmaster.com and grainger list these, along with just about every good hardware supply entity.

------------------------- ----------------

Also known as cold-forming and fluteless taps, these press threads into material without cutting it, so no chips are created. They produce stronger threads than other taps, but more torque is required to drive them into the workpiece. With no need to reverse while tapping, these taps create threads more efficiently than standard taps and are often used for production work.

Use uncoated taps for short production runs. Titanium-nitride (TiN) coated taps resist heat and wear better than uncoated taps, so they'll last longer when threading similar material.

Plug-chamfer taps are a versatile choice for most tapping applications. They have 3-5 chamfered threads to press threads into the workpiece, so they're good for start-to-finish tapping.

Bottoming-chamfer taps form threads in the workpiece with just 1-2 chamfered threads. This short chamfer lets them thread holes closer to the bottom than other taps, but they require more torque to start threads.
Inch
Thread

Drill Bit

Plug Chamfer


Bottoming
Chamfer
Size Lg. Overall
Lg. Size Decimal Size
Equivalent Thread
Type Pitch Dia.
Limit Each Each
Uncoated High-Speed Steel
4-40 5/16" 1 7/8" 38 ga. 0.1015" UNC H3 2531A14 $14.17 2531A26 $14.17
5-40 5/16" 1 15/16" 33 ga. 0.113" UNC H3 2531A37 14.17 2531A49 14.17
6-32 3/8" 2" 1/8" 0.125" UNC H3 2531A16 11.67 2531A27 11.67
8-32 3/8" 2 1/8" 25 ga. 0.1495" UNC H3 2531A17 11.67 2531A28 11.67
10-24 1/2" 2 3/8" 11/64" 0.1719" UNC H4 2531A18 11.67 2531A29 11.67
10-32 1/2" 2 3/8" 16 ga. 0.177" UNF H4 2531A39 11.67 2531A53 11.67
12-24 15/16" 2 3/8" 8 ga. 0.199" UNC H4 2531A61 12.52 ______ __
12-24 1/2" 2 3/8" 8 ga. 0.199" UNC H4 ______ __ 253 1A62 12.52
1/4"-20 5/8" 2 1/2" 1 ga. 0.228" UNC H4 2531A21 12.38 2531A31 12.38
1/4"-28 5/8" 2 1/2" 15/64" 0.2344" UNF H4 2531A43 12.38 2531A54 12.38
5/16"-18 11/16" 2 23/32" L 0.29" UNC H5 2531A22 13.75 2531A32 13.75
5/16"-24 11/16" 2 23/32" M 0.295" UNF H5 2531A44 13.75 ______ __
3/8"-16 3/4" 2 15/16" S 0.348" UNC H5 2531A23 15.68 2531A33 15.68
3/8"-24 3/4" 2 15/16" T 0.358" UNF H5 2531A46 15.68 2531A56 15.68
1/2"-13 15/16" 3 3/8" 15/32" 0.4688" UNC H5 2531A25 26.73 2531A34 26.73
1/2"-20 15/16" 3 3/8" 12.25 mm 0.4822" UNF H5 2531A47 26.73 2531A57 26.73
5/8"-11 1.09" 3.81" 17/32" 0.5312" UNC H7 2534A32 41.83 2534A34 41.83
Titanium Nitride (TiN) Coated High-Speed Steel
4-40 5/16" 1 7/8" 38 ga. 0.1015" UNC H3 2534A31 19.92 2534A33 19.92
6-32 3/8" 2" 1/8" 0.125" UNC H3 2534A11 14.94 2534A21 14.94
8-32 3/8" 2 1/8" 25 ga. 0.1495" UNC H3 2534A12 14.94 2534A22 14.94
10-24 1/2" 2 3/8" 11/64" 0.1719" UNC H4 2534A13 14.94 2534A23 14.94
10-32 1/2" 2 3/8" 16 ga. 0.177" UNF H4 2534A14 14.94 2534A24 14.94
1/4"-20 5/8" 2 1/2" 1 ga. 0.228" UNC H4 2534A15 15.83 2534A25 15.83
1/4"-28 5/8" 2 1/2" 15/64" 0.2344" UNF H4 2534A16 15.83 2534A26 15.83
5/16"-18 11/16" 2 23/32" L 0.29" UNC H5 2534A17 17.62 2534A27 17.62
3/8"-16 3/4" 2 15/16" S 0.348" UNC H5 2534A18 20.08 2534A28 20.08
Metric
Thread

Drill Bit

Plug Chamfer


Bottoming
Chamfer
Size Pitch,
mm Lg. Overall
Lg. Size Decimal Size
Equivalent Pitch Dia.
Limit Each Each
Uncoated High-Speed Steel
M3 0.5 5/16" 1 15/16" 7/64" 0.1094" D5 2534A35 $15.56 2534A41 $15.56
M4 0.7 3/8" 2 1/8" 3.7 mm 0.1456" D6 2534A36 12.79 2534A42 12.79
M5 0.8 1/2" 2 3/8" 14 ga. 0.182" D7 2534A37 12.79 2534A43 12.79
M6 1 5/8" 2 1/2" 7/32" 0.2188" D8 2534A38 13.58 2534A44 13.58
M8 1.25 11/16" 2 23/32" 7.4 mm 0.2913" D9 2534A39 15.11 2534A45 15.11
Titanium Nitride (TiN) Coated High-Speed Steel
M3 0.5 5/16" 1 15/16" 7/64" 0.1094" D5 2541A31 15.80 2541A41 15.80
M4 0.7 3/8" 2 1/8" 3.7 mm 0.1456" D6 2541A32 15.73 2541A42 15.73
M5 0.8 1/2" 2 3/8" 14 ga. 0.182" D7 2541A33 15.53 2541A43 15.53
M6 1 5/8" 2 1/2" 7/32" 0.2188" D8 2541A34 16.23 2541A44 16.23
M8 1.25 11/16" 2 23/32" 7.4 mm 0.2913" D9 2541A35 19.20 2541A45 19.20
M10 1.5 3/4" 2 15/16" U 0.368" D10 2541A36 21.47 2541A46 21.47
M12 1.75 15/16" 3 3/8" 11.2 mm 0.4409" D11 2541A37 35.67 2541A47 35.67




 
Chevytu 
Senior Member
Posts: 248
Chevytu
Loc: Argentina
Reg: 12-29-02
07-09-20 04:45 PM - Post#2798299    
    In response to IgnitionMan

Thanks for all the replies and info.
Think 65_Imp is on the same page here:

"...but both internal and external threads can be created using a thread forming technique. Creating internal threads is call thread forming and uses a thread forming tap"

Searched this stuff up, very ineresting.

1966 Chevy II SS, BBC


Edited by Chevytu on 07-09-20 04:48 PM. Reason for edit: No reason given.

 
65_Impala 
Very Senior Member
Posts: 4491

Reg: 12-29-02
07-09-20 06:34 PM - Post#2798311    
    In response to Chevytu

Yup, you can't roll an internal hole through a die, as you already posted. You might find the taps called roll forming taps - the word roll gets stuck into the tap description because of thread rolling not cutting. But the process of tapping using a thread forming tap certainly doesn't involve forming the threads by rolling since it's impossible to roll a hole through a set of dies.

Here's video of a thread rolling machine working in case someone doesn't know what they do or how they work.

https://www.youtube.com/watch?v=Mlfq_Pbh6PQ
https://www.youtube.com/watch?v=vtHUM5IQIfA

Can't run holes through either of these machines!

Both appear to be using flat dies. A cylindrical die machine constantly turns in the same direction and can roll multiple blanks at once. Feed one in and and soon as it starts moving between the dies another one can be fed in.



 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
07-10-20 01:33 PM - Post#2798358    
    In response to 65_Impala

:sad :



 
IgnitionMan 
Valued Contributor
Posts: 3769

Reg: 04-15-05
07-10-20 01:37 PM - Post#2798359    
    In response to Chevytu

Chevytu, as I alluded, it is best NOT to get into a battle of wits with persons like him, ones that are completely unarmed.

Let it go, he is only a copy and paste mis-informer.



 




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