drilling hole in an axle

wondering if any one had a good brand of drill bit 1" or 3/4" hole size for drilling lighting holes in a forged straight axle and also drilling the wishbones...i tried one and destroyed my drill bit...what do you guys think of the step drill bits?..what are good durable grill bits that will last atleast the job???

Hole saw, oil, and slow rpm.

Center punch first.

Unkl Ian said:

Hole saw, oil, and slow rpm.

Center punch first.

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Yes, good brand of hole saw not a cheap HF one, lots of oil and slow rpm and not a lot of pressure.

Takes a while but look so cool!

get a lennox or even a rigid from home depot... have had good luck with both. and use plenty of oil. take a trip down the plumbing isle and grab some tread cutting oil for threading black pipe. Stuff works great.

Cut mine with a torch and cleaned it up with file. Way faster........

fuzz said:

Cut mine with a torch and cleaned it up with file. Way faster........

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wow fuzz-that HAS been "lightened"
just curious (certainly not trying to be argumentative) but it seems as if removing that much material would weaken the axle.....just wonderin'[S

good advice

thanks for the good advice.....what do you guys think of the step bits?

I don't think those wedge/pyramid shape bits are 'real' tools--kinda gadgets.. I do drill my axles in stages--Like I start withan 1/8 pilot hole and progress up in 2-3 steps to the 3/4" or 1". I make a drilling jig that fits snug into the forged axle webs and has the two 1/8" holes spaced correctly. I center the first hole in the axle and walk my way out to the ends by securing the jig to the drilled hole and drilling the next.

I am pretty sure a round hole in the web only, doesn't weaken the axle, although I'm leery of the long slots.. But-- I've never seen a forged axle fail on a car -- drilled or slotted. I've seen tube axles bend and collapse though!!! I think they rusted from the inside or were too thin to start... I guess we are 'trusting' of the aftermarket when we'd be better to just trust our own judgement. I think most of us over build bigtime--thats a good thing

PA41

This is one area where that saying "measure twice cut once" really applies. If you are off just a tad on any hole it will show up and be very apparent. We make a little "car" out of scrap steel that just fits down in the inset so we can slide it along the depression. It has a little hole in the center just big enough for a sharpie permanent marker. As we slide it along the depression it makes a mark down the centerline. Now we have the center of each hole to be drilled.

Next we lay out fender washers that are about the same size as the holes you are going to want in the axle. We space them evenly on that centerline until we get a pleasing spacing. Usually about 14 to 16 holes seem to be what fits from our experience. Once we have a pattern we like we recheck the spacing between the washers and scribe a cross line on the centerline. That will be the center of each hole we drill.

We centerpunch each hole and use a 3/16 bit to drill each hole first. Next we use a 7/8 or 1 inch holesaw and drill down through each hole letting the holesaw do the work. Lots of cutting oil and a lot of patience let the hole come out nice and clean. You will still need to run a round sanding/grinding stone through each one to smooth it out a little, then you are done.......at least for THAT hole...........you still have to repeat the process 13 or 15 more times.

Don

hotrod preacher said:

wow fuzz-that HAS been "lightened"
just curious (certainly not trying to be argumentative) but it seems as if removing that much material would weaken the axle.....just wonderin'[S

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If you think about it you'll realize that all the load and stress is on the ends of the axle, from the radius rods to the king pins. The "I" beam part of the axle only holds the ends together in alignmentt. I have used that axle on a heavy [3500 lb car] and even jacking up the car from the center, there was no flexing or bending. Henry made those axles out of the finest steel ever produced. No outsourceing from China!!


But scary lookin is kool, don't ya think??[cl

well i'd never thought about it from that point of view, fuzz.....[S


thanks for the info-once again i learn something from this site's people...another reason i like the RRR

I have one like that too but it look way way too scary so I ordered a new one. This one I will not use, I just dont trust it,,,,

Pat yourself on the back for the smart decision not to run that axle. I have hit some pretty hard seams on interstate bridges at 70 mph, and I could just see that one you have collapsing at the wrong time.

You made a very good decision. [cl

Don

That one looks like too much cut out but you could have filled it in and used it. Easy to weld on those axles since they were high quality steel.

I bought it to mock up the front of my truck, the old guy I bought it from used it on his 32 roadster and he drove it all of the time. I thought about having it filled but decided the time and money was not worth it and picked up a 4" dropped axle, new spring all hangers new hair pins, and had it powder coated for what it was going to cost me to have this one filled.

fuzz said:

That one looks like too much cut out but you could have filled it in and used it. Easy to weld on those axles since they were high quality steel.

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Yeah--They are real pleasant to weld on. Good forgings. I can see getting 'creative' on the inserts on that axle for a 'forlookinat' car. Like maybe cutouts of hearts and spades, or even a line of Xs, or / \ / \ make a truss out of the area. Or--maybe your name like a cowboy belt.. They would all reinforce the area of the slots.

It surely can be fixed??

Hate to pitch stuff.

PA41

Just got done drilling a stock 37-41 axle with 7/8 holes went through two hole saw bit's, I just did to turn it around and sell it looks great dont think i'l do very many more pretty time consuming with my cheap drill press.

I have used hole saws with oil but i find it works better if while you are drilling you blow the shavings away with the airhose as a hole saw has no provisions/flutes to remove them. Using air also keeps the holesaw bit cool and it needs to turn slowly, say 100 to 150 rpms. Using a holesaw is better than drill bits as you are removing a slug instead of turning all the metal into shavings.