Drilling holes in spring steel

[Isaac S]

One of the most frequent questions I get is how to drill or punch the holes for the saw bolts in the blade. By far, this is the easiest way I have found. It is fast and moderately inexpensive, but does require a drill press. Actually, a drill press is not absolutely necessary, but it is strongly recommended.

I use a solid carbide spade drill bit. The spade bit design is specifically designed for drilling sheet metal, and eliminates any grabbing as it exits the hole. However, this also means it will not drill wood, which is a lesson I learned the hard way.

300758

Because it is carbide, it eats through the spring steel with no need for annealing or coolant. It takes just a few seconds for each hole.

In this first video, I drill the holes for the handle in real time. On the third hole, I do not go all of the way through while the blade is in the handle, as the exit hole in brass leaves a large burr that makes it difficult to remove the spine and blade from the handle. Once I have the hole located, I remove the handle and complete the hole. There is a slight burr on the back side, but it comes off in a few seconds witha the deburring wehel



http://www.youtube.com/watch?v=tAwAUWomd0I



In this next video, I drill a few holes through 0.042 spring steel. This is typical 1095, Rc 48-51.


http://www.youtube.com/watch?v=iKB99RsDPH4



In the US, these bits run about $10-15 shipped for a 3/16" bit. I don't know where to begin looking in Australia, but eBay might be worth a look.

[Simplicity]

Isaac ,
They look fantastic.
They went through the saw plate with what seems very little effort.
Do you use any cutting fluid ?
Also do they only come in the size you mentioned ?
Or are there other sizes available?
And last were the ones in the little video new or have they been through a few holes all-ready ?
I suppose what I am asking is how long do they last or are they able to be resharpened ?
Are few questions I know .
Thanks for posting as u are properly aware there has been quite a bit of discussion here on making the saw bolt holes .
Cheers
Matt


Sent from my iPhone using Tapatalk 2

[Isaac S]

Isaac ,
They look fantastic.
They went through the saw plate with what seems very little effort.
Do you use any cutting fluid ?
Also do they only come in the size you mentioned ?
Or are there other sizes available?
And last were the ones in the little video new or have they been through a few holes all-ready ?
I suppose what I am asking is how long do they last or are they able to be resharpened ?
Are few questions I know .
Thanks for posting as u are properly aware there has been quite a bit of discussion here on making the saw bolt holes .
Cheers
Matt


No cutting fluid is needed.

They come in a wide variety of sizes. Not sure about metric, but I know they are readily available in 32nds of an inch, and at least some 64ths. Anything close will work for this application so long as it's oversized.

The ones in the video have probably drilled 50 or more holes. They last nearly indefinitely unless you abuse them, and then they can chip. The edge geometry is very basic, so they are easy to touch up if you have diamond wheels or stones.

The one thing they don't like is shock or vibration. You can't slam it into the work, and you can't push it faster than it wants to go. And they do work best in a drill press.

I am aware of the discussion (both here and elsewhere). I've mentioned these before, and finally realized that a video might be more convincing than just my words.

[_fly_]

there is a guy on ebay au, but they come from US.
surplustooling items - Get great deals on items on eBay Stores! (http://stores.ebay.com.au/surplustooling)
so postage is the killer, seeing they fit in a standard envelope.

[planemaker]

Very nice presentation Isaac. Thank you. :2tsup: It should also be mentioned that Isaac's saw bolts have a matching 3/16" stem dia. This detailed article from Isaac's blog site is well worth reading to better understand the full process he follows. Saw build along (http://www.blackburntools.com/blog/saw-build-along-handle-part-viii/)

[Simplicity]

Thanks Isaac
Fantastic


Sent from my iPhone using Tapatalk 2

[planemaker]

The solid carbide spade drill bits in imperial are not available on ebay/Aus from the search I did. Looking for 5/16" dia, that would suit the saw bolts I use, I could only find 1 international supplier that would post to Aust, and the total cost was around $42 delivered.:doh:

[jhovel]

Not quite a woodworker's project, but because of the simple geomety, these can be made from broken solide carbide milling cutters or shanks of other broken solid carbide tools.
You do need a diamond wheel or a green wheel though. Seeing that the proces of small diamon wheels are about $15, and they are useful for all kinds of tipped and solid tools, their purchase and creativity in other carbide tools are not out of the realms of reasonable investment.....

[hiroller]

I use a multi purpose bit. It looks like a masonry bit but has carbide cutting teeth.
Works as well as the solid carbide bit. Costs about $8 from your local hardware.
The 2 brands I have used are P&N and Bosch.

[rob streeper]

I recently secured a Roper Whitney No. 8 punch tool with a large set of punches and dies. As a preliminary evaluation of its' capacity I tested it on a scraper blade made for use in reciprocating saws. The owner of the broken blade brought it to me and asked if I could put a wooden handle on it. The blade is about 0.055" and is easily as hard as saw steel.
Here is a pic of the punch secured in my 8" bench vise for convenience.

301509

The manufacturer claims "1/4" hole through 1/4" iron", we'll see.

301510

Here's the business end.

301511

Mark hole positions.

301512

Line up the punch point with the marks.

301514

Squeeze twice and we have

301515

and no damage to the punch or die.

301516

Alignment will be easier using transfer punched saw steel. The paint on this piece, combined with the slanting afternoon sun made alignment difficult because of reflections. Overall I am pleased. I will use this to punch undersized holes in my saw plates and then ream them to size.

[Heavansabove]

I recently secured a Roper Whitney No. 8 punch tool with a large set of punches and dies.

The manufacturer claims "1/4" hole through 1/4" iron", we'll see.

Rob, looking at specs of these online, the quoted thickness of steel means mild steel. For tool steel...

Cheers
Peter

[BobL]

One trick to reduce the grabbing effect as bits pass through the hole is to flip the work piece over after partial breakthrough has been achieved.

I've used old masonry or tile cutting bits reshaped on a green wheel to do this sort of thing.

One of the most challenging holes to drill is through the center of a hardened steel bearing wheel of a chainsaw bar nose sprocket.
The same shaped carbide bits seem to do this easily enough but because this is a lot harder and thicker than saw plate the bit can get very hot so some coolant helps.

[pmcgee]

Drake hardware ... early 20thC I guess ...

301606

[DSEL74]

Interesting that it appears to screw down rather than lever by squeezing.

[pmcgee]

I'd guess, like a cider press (eg), you can generate more force .. or at least a slowly increasing force with a screw ... depending on the thread ...
:shrug:
Paul

[hiroller]

I found this article about a home made punch for spring steel.
Looks pretty straightforward and effective.
Device For Punching Holes In Saw Blades, Clock Springs, Etc (http://chestofbooks.com/home-improvement/workshop/Handy-Man/Device-For-Punching-Holes-In-Saw-Blades-Clock-Springs-Etc.html)

Description


This section is from the book "Handy Man's Workshop And Laboratory", by A. Russell Bond. Also available from Amazon: Handy Man's Workshop And Laboratory.


Device For Punching Holes In Saw Blades, Clock Springs, Etc


The device shown in side and end elevation at A and B respectively, is made from any old piece of iron or steel, the latter being preferable, as it can be tempered after it is made. The writer is at present using one made of a piece of 5/8-inch square iron some 3 inches long, which has a hole (the same size as the hole to be punched) drilled through it near one end. After drilling the hole cut down with a hack saw as far past the hole as will clear the material to be punched, care being taken that the hole is at right angles to the saw kerf. For a punch use the broken shank of a twist drill of the same size as the hole. This makes a very efficient punch, and the face of the punch is improved by carefully grinding it on a small 3 1/2-inch diameter emery wheel in the manner shown at C; as by this means the face of the punch is slightly hollowed, and its shearing effect is increased.




Fig. 117 - Method of punching holes in saw blades, etc..
302259


The application of the device in punching a hack-saw blade is illustrated at D. This simple apparatus if properly made will do excellent work on saw blades and springs. The writer has in this way punched a 5/32-inch hole through the blade of a Disston rip saw without distorting the blade or raising a burr around the edges of hole. One can easily make several of these in different sizes, but for hack-saw blades 5/32 inch is a suitable size. It is of course imperative that the punch be a good fit in the hole. The application of a somewhat heavy hand hammer is effective.