Need Steel Drilling Help

[UpSideDownClown]

Hi all - newbie here, fabricating a specialty tool for automatic transmissions, and due to limited resources have to find inexpensive solutions. Each tool will use (2) flat bars, A36 steel, 3/8 thick, 1 inch wide. For each bar, I need to drill 2 holes with finished size of either 23/64 or 3/8, and one hole with finished size of 7/16. I have managed to use Harbor Freight titanium bits with a 1/2 corded hand drill to prove out the design but not much more. I invariably drill the smaller holes off-center, and yesterday I actually managed to drill the big hole at an angle, top to bottom. I mean, it is visible to the naked eye that the hole through the bar was crooked. And what I notice is that some of these cheap bits cut like a beast, and others sound different, simply laugh at me, and of course get very hot and burn. So not only is the bit quality suspect, it's inconsistent from one bit in the set to the next. I step up in size many times, starting very small after punching a pilot notch.

So...I'm wondering if I got a cheapo 8" drill press at Harbor Freight, I might solve the off-center thing, and it would also potentially solve any drill speed issues. I'm thinking the risk there is that the part you put the work piece on would want to move down vertically as you drill, so maybe I could block it up underneath with wood or bricks, to keep it from moving. Then, I wonder if I could use a drill bit of the above mentioned sizes, to achieve the finished size in one shot, and avoid all of the stepping up. Might that be doable? And then the final piece would be the bit; should I go to a brand-name cobalt bit? Thank you; this is not really my bailiwick, as you can no doubt tell.

 

[zendriver]

What kind manufacturing quantities are you thinking?

To do it right, build a jig and use drill bushings with it.

The jig will hold the piece in place and the bushings will keep the bit from moving, to the side. positioning will be near perfect every time. Production will increase rapidly.

Pardon Our Interruption...

Definitely need a drill press.

Good luck.

 

[UpSideDownClown]

What kind manufacturing quantities are you thinking?

To do it right, build a jig and use drill bushings with it.

The jig will hold the piece in place and the bushings will keep the bit from moving, to the side. positioning will be near perfect every time. Production will increase rapidly.

Pardon Our Interruption...

Definitely need a drill press.

Good luck.

Thanks. I'll probably only sell like 20 of these kits. I have no idea how to build a jig.

 

[Lwel9226]

A drill press like you mentioned would be a huge help, but an upgrade/upsize to a bigger better machine would be a wise investment....

LynnW

 

[Jswain]

Small drill press and stop stepping up in so many sizes. Start with 1/4" then go to your finished size. Slowest speed on the drill press and use enough downforce to keep it drilling. Could use a splash of rapid tap when drilling to keep the bit cool

You could try your finished size right off the hop but the drill press may be underpowered. A 1/4" pilot hole will go very fast even on a small drill press.

Drill bits you basically get what you pay for. Nearly any decent hss drill bit would do what you're looking for, as long as you don't step up in too many increments dulling the shoulders, use enough downforce, use cutting oil, and slow the rpm accordingly.

 

[nadogail]

Buy a Drill Press, it does not need to be a high quality production machine, just a medium grade import, mine came from Taiwan.

Clamp your work in a vise, and be generous with the cutting oil. Use a Center Punch and sharp quality drill bits.

Watch the curl coming from the steel as you drill it, when you are getting long curls you will know you have the feed and speed dialed in.

 

[LopezBart]

Buy a Drill Press, it does not need to be a high quality production machine, just a medium grade import, mine came from Taiwan.

Clamp your work in a vise, and be generous with the cutting oil. Use a Center Punch and sharp quality drill bits.

Absolutely this. For the best accuracy in hole location, a center drill can be used before the first drill bit. With a bit of care, it's possible to hold pretty tight tolerances.

 

[strength_and_power]

If it is something you are wanting to sell and want a professional looking product, why not just have the piece laser cut if it’s just 1” x 3/8” flat bar? Holes would be exact in both size and location. Laser Bros and Send, Cut, Send are two places that come to mind

 

[ez-duzit]

Thanks. I'll probably only sell like 20 of these kits. I have no idea how to build a jig.

You're not likely to sell any at all because:

a) you are not equipped to do a proper job
b) you don't have the skills to do a proper job
c) you have no idea how to go about it

 

[esben57]

You're not likely to sell any at all because:

a) you are not equipped to do a proper job
b) you don't have the skills to do a proper job
c) you have no idea how to go about it

Get down off the fence, duz.

 

[zendriver]

You're not likely to sell any at all because:

a) you are not equipped to do a proper job
b) you don't have the skills to do a proper job
c) you have no idea how to go about it

That’s the American spirit!

He can’t do it, so he shouldn’t even try.

 

[Robinson1]

Buy the harbor freight drill press. While you’re there buy a center punch as well. Make a template for hole location (can be as simple as a piece of poster board). Use cutting fluid. Heck WD40 is better than nothing. Decent quality HSS bits will do what you want. A Cobalt bit from any box store will likely do what you want.

I’ve made a heck of a lot of randomness with nothing more than a harbor freight drill press. A random box of bits from a half dozen sources (all cheap junk) a angle grinder, bench vise and big hammer!

 

[Dave455]

Firstly, you need a drill press. This ensures everything is at right angles and enables you to apply the steady downforce you need.

Secondly, you need decent drill bits. Forget anything from Harbor Freight, no matter if it is claimed to be made of unobtanium. Go to somewhere like MSC, or any other industrial supplier, and for anything tougher than mild steel (I think A36 is) get Cobalt or TiN coated drill bits from a well regarded drill manufacturer.

Centre punch where you want the hole to be located, or centre drill or spot drill it. Once you have done that, put a “pilot” drill of say 1/8 down, and maybe even another of 3/16 or 1/4. Use some cutting fluid (also from MSC).

If you want a really high quality finish, drill the hole slightly undersize, and use a reamer to finish, but a good quality drill bit should give a reasonable finish.

If I was going to drill 40 holes I would definitely be making a jig. It need not be anything with bushings, just something that you can fix to the base of the drill press that locates the workpiece in the same place each time.

 

[UpSideDownClown]

Small drill press and stop stepping up in so many sizes. Start with 1/4" then go to your finished size. Slowest speed on the drill press and use enough downforce to keep it drilling. Could use a splash of rapid tap when drilling to keep the bit cool

You could try your finished size right off the hop but the drill press may be underpowered. A 1/4" pilot hole will go very fast even on a small drill press.

Drill bits you basically get what you pay for. Nearly any decent hss drill bit would do what you're looking for, as long as you don't step up in too many increments dulling the shoulders, use enough downforce, use cutting oil, and slow the rpm accordingly.

Thanks, jswain. The drill press I see at HF is 1/3 HP, 2.3 amp.

 

[UpSideDownClown]

Thank you all for the help and quick responses. It looks to me like I could buy a few good quality bits along with the drill press and be in business. As for not being capable of doing it, well, I already have, so there's that. I'm just looking to improve the process and reduce wear and tear on my body. My tool costs a fraction of the factory tool, and actually works better; it does not require the transmission builder to take the case half to a press like the factory tool does. As for outsourcing machining to a shop, simply too expensive, especially in NorCal, and shipping costs have spiraled out of control if I look to go out of my area.

USDC

 

[MushCreek]

Good drill bits aren't that expensive, and will drill better and more accurately. Depending upon how good the holes need to be, you should be able to center drill, then go right to finished size. For a cleaner hole, drill 1/64" undersize, then ream. A reamer will cost a lot more that a drill bit, though. Use cutting oil. Make sure the drill press you buy is capable of slow enough RPM for the size tools you are using.

I have a milling machine, which makes a job like this a piece of cake. If I only had a drill press, I'd make a fixture, as others have mentioned. A fixture would consist of a sturdy steel plate with hardened drill guide bushings pressed in. You clamp it to the part, and each piece will be exactly the same. I've made a lot of them for guitar builders. The problem in a home shop is A) Getting the hole locations accurately, and B) Making an accurate hole to press the bushing into.

If the product is that good, I would think that you could sell a lot more than 20 of them, making it worth putting in some more investment and effort up front. If you sell one that's kind of iffy and the word gets out, no one else will want to buy one. I spent part of my career doing production machining, and the rest of it doing tooling, so I have a lot of experience with this stuff. From here, I have no idea if this is a $10 tool or a $100 tool. maybe it only fits a 1956 Packard, so there really only is a potential market for 20 of them.

 

[Firebrick43]

Any drill press is going to be better than hand drilling but 8” on is going to be questionable even in steel.

I would suggest looking for a 12” or 14” with a low speed pulley set up especially if you are going to do much drilling in metal in the future.

Doesn’t have to be a new machine.

Second a vise to hold your work helps tremendously

As far as drills and accuracy.

Start with a center punch to locate where you want to drill.

Use a wiggler to locate the punch mark directly under the spindle.

Then use a center drill #3 size would be good for that size hole.

Once it’s spotted and sunk down to the cone on the center drill you can use a 1/4” size drill first then switch to the larger finished size.

If you want the best in diameter accuracy you drill out to 1/32 under size and use a reamer to finish.

In all operations use a cutting oil for lube and cooling.

As far as drill bits, HF are some of the most inconsistent ones I have ever used. One might be barely acceptable and the one next to it dead soft.

Get good bits such as Cleveland, Chicago Latrobe or Viking. I would take their HSS bits over crappy import TIN coated ones.


Mrpete222

The above link will take you to a good shop teacher that has great videos for beginners.

Watch his videos on “use and care of drills”, “use and care of reamers” , “how to use a wiggler” and maybe one on accurate hole layout.

 

[UpSideDownClown]

Good drill bits aren't that expensive, and will drill better and more accurately. Depending upon how good the holes need to be, you should be able to center drill, then go right to finished size. For a cleaner hole, drill 1/64" undersize, then ream. A reamer will cost a lot more that a drill bit, though. Use cutting oil. Make sure the drill press you buy is capable of slow enough RPM for the size tools you are using.

I have a milling machine, which makes a job like this a piece of cake. If I only had a drill press, I'd make a fixture, as others have mentioned. A fixture would consist of a sturdy steel plate with hardened drill guide bushings pressed in. You clamp it to the part, and each piece will be exactly the same. I've made a lot of them for guitar builders. The problem in a home shop is A) Getting the hole locations accurately, and B) Making an accurate hole to press the bushing into.

If the product is that good, I would think that you could sell a lot more than 20 of them, making it worth putting in some more investment and effort up front. If you sell one that's kind of iffy and the word gets out, no one else will want to buy one. I spent part of my career doing production machining, and the rest of it doing tooling, so I have a lot of experience with this stuff. From here, I have no idea if this is a $10 tool or a $100 tool. maybe it only fits a 1956 Packard, so there really only is a potential market for 20 of them.

MushCreek - I expect to ask $150 for the kit, and it's a 2-in-1 kit which performs two functions during overhaul of the transaxle. The transaxle is a high gear count unit made by a third-party company, so it's used by multiple automakers and is currently in production. These holes I'm drilling are not critical; a bolt just needs to slide through there. Obviously with only 1" width in the bar, it needs to be pretty centered, but I have no problem from a marketing standpoint stating that the only way I can sell the toolkit for so little is that I have to do some operations in-house, and that they may not look perfect, but absolutely get the job done. I did have to go to a shop with CNC capabilities for a special plate built to specs, but luckily found a place out of state who must have an incredible contract with shippers because the freight costs are almost nothing, and he charges a fraction of what my local guy wanted. And, that local guy with all his CNC tools couldn't cut a centered hole in the middle of one of the plates; it was offcenter. Several other places wouldn't even quote it, or lied that they would and blew me off. The world has changed, and I want to keep as many processes in-house as possible.

 

[AffableCurmudgeon]

Love to see your design. Post a pic.

 

[UpSideDownClown]

AffableCurmudgeon...not by chance Curmudgeon Transmission on uTube?

USDC

 

[AffableCurmudgeon]

AffableCurmudgeon...not by chance Curmudgeon Transmission on uTube?

USDC

Nope, I am not in car related business. Just a hobbyist.

 

[UpSideDownClown]

Nope, I am not in car related business. Just a hobbyist.

I'll get a snapshot of a working prototype bolted to the case and post up when it gets light out here...

 

[cannuck]

USDC

How are you doing your layout? What is your tolerance for center-to-center distance and how are you measuring?

Don't even THINK about doing this in the 8" HF press. You need something with a stable table and a 1/2" chuck if you intend to do this more than once. As already suggested: look for something larger on the used market. When you set it up, measure the table to be dead horizontal at 90 degrees to a ground bar in the chuck in 2 axis. Do your layout on machinist's blue, use an automatic centerpunch to hit the layout lines exactly where they cross. Use centerpunch with freshly ground tip into that little punch mark. Center drill as mentioned above THEN you can expect a decent drill bit to make your hole close enough to what you want or need (note questions about tolerance). Buy a 90 degree countersink and deburr your holes on BOTH sides with it.

You can do incredibly accurate holes IF you take the time to learn how to do the layout. I regularly do bolt patterns that match up well within the tolerance provided by nominal size holes to actual size fasteners, but it takes a lot of time and care. You learn to do it by DOING it - you are on the correct and only path.

 

[mark-NJ]

May I also add: 135 degree bits are a Godsend. They eat steel better than 118 degree ever could.

 

[Zewnten]

@UpSideDownClown ignore @ez-duzit, I've never seen him do any thing on here other than talking ****, as no one is mommy's-extra-most-bestest does-everything-perfect as him, (it's why he fits in so well at practical machinist). Life is about learning not internet points but he hasn't learned that yet.

If your trying to make a one off your system would work fine but for production runs I'm going to suggest in either partnering with a local machine shop to make up batches or visit a small scale metal/machine shop and see what they do. Most of them I've met are good guys who love showing people what they do and will give pointers and such. Then you can see what equipment you need to. Right now in my area there are several multi headed drill presses that would be perfect for this, but I do think the easier way would be working with a good machinst/metal worker to handle the production side and let you focus on the marketing.

 

[larry_g]

https://www.mscdirect.com/browse/tn/Holemaking/Drilling-Drill-Bits/Metalworking-Multipurpose-Drill-Bits/Screw-Machine-Length-Drill-Bits?navid=2106190&refinements=Tool+Material%3AHigh-Speed+Steel--Drill+Bit+Size+%28Inch%29%3A3%2F8--Point+Type%3ASplit

If I were doing this job I'd go to the above site and get a screw machine length, split point, hss bit. The short length is stiffer and usually more on size with the hole drilled. The split point helps to start the hole eliminating the pilot hole. and forget the coated bits. The good coated bits are specialized and the retail stores are little more than coloring. Just buy a couple of each size you need.

 

[Retired dozer fixer]

Drilling steel means SLOW speeds. Drill a hole 3/8” at 150 rpm and drill the same at 1000 rpm. See how long your bit lasts. Even a cheap bit will work

 

[UpSideDownClown]

https://www.mscdirect.com/browse/tn/Holemaking/Drilling-Drill-Bits/Metalworking-Multipurpose-Drill-Bits/Screw-Machine-Length-Drill-Bits?navid=2106190&refinements=Tool+Material%3AHigh-Speed+Steel--Drill+Bit+Size+%28Inch%29%3A3%2F8--Point+Type%3ASplit

If I were doing this job I'd go to the above site and get a screw machine length, split point, hss bit. The short length is stiffer and usually more on size with the hole drilled. The split point helps to start the hole eliminating the pilot hole. and forget the coated bits. The good coated bits are specialized and the retail stores are little more than coloring. Just buy a couple of each size you need.

Thank you. I'll take those specs somewhere else online; looks like MSC uses the Rock Auto model; make your money on the shipping charge.

 

[whateg01]

I have found with cheap drill bit sets, not only is the quality of the hss questionable, but several times I've run across still buys so badly ground, some are actually backwards. Iow, the cutting lip is not the tallest part of the flute. Learning how to off hand sharpen drills will help you get accurate holes (accurate for a drill bit) and extend the life of the drill bits you have.

 

[UpSideDownClown]

Wow; incredible response here. If I don't thank you or respond to your message specifically don't be offended. THANK YOU!

USDC

 

[UpSideDownClown]

Drilling steel means SLOW speeds. Drill a hole 3/8” at 150 rpm and drill the same at 1000 rpm. See how long your bit lasts. Even a cheap bit will work

As I understand it, the drill press has a cheatsheet for where to set the belt for correct drill speed range. Definitely one of the reasons I was wanting to start using the drill press. I am likely drilling too fast by hand.

 

[UpSideDownClown]

Buy a Drill Press, it does not need to be a high quality production machine, just a medium grade import, mine came from Taiwan.

Clamp your work in a vise, and be generous with the cutting oil. Use a Center Punch and sharp quality drill bits.

Watch the curl coming from the steel as you drill it, when you are getting long curls you will know you have the feed and speed dialed in.

Thanks. Yeah, curls aren't exactly happening right now...! LOL More like specks!

 

[UpSideDownClown]

Pic of working prototype of the bars

USDC

 

[MushCreek]

I've had very good luck with Triumph Twist Drill Thunderbit.

 

[mark-NJ]

And most of all, remember: you're either making chips or your making heat. If chips / spirals aren't coming out, STOP.

 

[rdoty]

I suspect the cheapest way to get 20 of these is to have a service company like SendCutSend laser cut them. The cost of finished parts is likely comparable to your cost for the raw steel and they will be more accurate than you can do.

If you want to do it yourself, look at getting a decent used drill press off of Craigslist or Facebook Marketplace. You want a metal drill press, which runs at low rpm and high torque. Something from the 1950's or 1960's can be surprisingly good. Make sure you get a 120 volt drill press; many of the industrial ones are 240 volt or 240 volt 3-phase.

After people here at Garage Journal pointed me to them I've become a fan of Harry J. Epstein and their Norseman drill bits. Industrial drill bits available in single sizes at good prices. With a decent drill press you can drill a 3/8" or 7/16" hole directly without a starter hole.

Get a drill press vise and bolt it down. This will position your holes more accurately and will be much safer - the drill will want to bind when it breaks through the back and a large chunk of spinning steel can quickly make for a bad day. Don't ask me how I know...

Be careful, don't do anything stupid, and be proud when you have done it!

 

[theoldwizard1]

Spend the money and get a used 1/2" drill press. You should be able to get one used for around $150

The tool you really want (but is probably out of your price range) is a "mag drill". Basically a small drill press that is held to the (steel) work piece by a strong electromagnet. The magnet can hold it in any position, including upside down ! (For you narrow pieces, just put 3 side by side on a work bench and drill the center one.) For thick steel, use an end mill instead of a drill. With an end mill, you may not need to ream the hole to get an accurate size.

 

[American Locomotive]

This is a simple project, and people are greatly over-complicating it. The $80 HF drill press would work just fine for the 3 holes you need to drill, as long as you kept it on the lowest speed. Buy 2 bits each of decent quality (even a "DeWalt" bit from Lowes or Home Depot would be fine), keep the bit lubricated with oil, and it will be fine.

As someone mentioned, the best way to do this would be to build a jig. A jig is basically just a wooden form (or your material of choice) that you clamp to the drill press. You just slide your piece of metal into the form, it stops at just the right place, and you drill your hole. You would then do all 20 of that hole in each piece. Then you clamp on and set up a jig for the other hole, and do the same again.

 

[UpSideDownClown]

I suspect the cheapest way to get 20 of these is to have a service company like SendCutSend laser cut them. The cost of finished parts is likely comparable to your cost for the raw steel and they will be more accurate than you can do.

If you want to do it yourself, look at getting a decent used drill press off of Craigslist or Facebook Marketplace. You want a metal drill press, which runs at low rpm and high torque. Something from the 1950's or 1960's can be surprisingly good. Make sure you get a 120 volt drill press; many of the industrial ones are 240 volt or 240 volt 3-phase.

After people here at Garage Journal pointed me to them I've become a fan of Harry J. Epstein and their Norseman drill bits. Industrial drill bits available in single sizes at good prices. With a decent drill press you can drill a 3/8" or 7/16" hole directly without a starter hole.

Get a drill press vise and bolt it down. This will position your holes more accurately and will be much safer - the drill will want to bind when it breaks through the back and a large chunk of spinning steel can quickly make for a bad day. Don't ask me how I know...

Be careful, don't do anything stupid, and be proud when you have done it!

rdoty - thank you for SendCutSend; I'll send them an RFQ right away. I am no hero, and have no particular desire to learn new skills at my age. It was the utter indifference, apathy and greed I was encountering from shops that had me doing this myself. And I'll also have them quote adjustment slots instead of the discrete end holes; that was my original design, until I got quotes for that. It's not feasible for me to get all case variations for this transaxle, so I made the bars longer than necessary in case buyers needed to cut their own mounting holes.

 

[strength_and_power]

The pieces look to be about 24” long. To make shipping easier, could you make a center piece with slots and 2 outer pieces with matching slots so you’d get your adjustability? Adjust to width needed and tighten 4 bolts to lock it into place. This would also allow the pieces to fit in a smaller box. The USPS medium flat rate box comes to mind. The rectangular box is around 12” on the long side. The boxes are free, they will even send you a bundle rather than going to the post office. Since it’s a flat rate box, you know what your shipping cost is so you come up with an all in price and offer “ free shipping”