Saw Blade Steel

[tnuckels]

I am trying to build a clip for my new Nautilus: http://www.candlepowerforums.com/vb/showpost.php?p=2406413&postcount=44 and after scouring the local hardware stores for donor items for this project and coming up short, decided to try a saw blade. I think I can get it to work by heating the metal to perform the bends, but am concerned that I'll alter the metal negatively, like cause it to fatigue more easily, or rust, etc., in the process.

If anyone has experience working with metal that is used in saw blades, like the type found on a common Stanley hand saw, I'd appreciate your comments.

 

[will]

You will have problems with a saw blade.

First - it is hardened. you will have to heat it - red hot to bend without breaking.

Second - you won't be able to cut it - it is hardened. You can grind it down.

but - for a couple of dollars for the blade - it is worth trying.

 

[dom]

Give the saw blades a miss -you can't bend them right over like you want in your picture -plus they will rust.

See if you can find a nice wide SS butter knife with uniform thickness blade.
They are made of stainless spring steel -though i think you still might have a bit of a task to fold the metal as aggressively as you want.

EDIT: Maybe even some of those cheap steak knives will be wide enough -not sure what width you need?

Cheers
Dom

 

[tnuckels]

Current design requires a sheet about 0.7" wide x 2.5" long, though looking at the mount hole spacing, center to center at 0.5", just now and imagining this wrapping around the body of the light, which is only 0.79", I'm starting to have second thoughts. I split the two legs loose from each other to allow for independent movement and easier placement, but the change in angle from one hole to the next when wrapping around that slim body may still be too much.

It all looks so good in 2D, but perhaps falls apart in the reality of a 3D world. Back to the drawing board and my ill suited software for this task, Visio.

Thanks for the pointers on saw blade metal WILL. Yes, hand saw blade vs. hack saw blade = DRAW, as it barely even leaves a scratch.

I had not thought to prowl the kitchen wares for my donor material. Thanks for the tip DOM. I can tell you've done this before.

I am able to achieve 90° bends in the saw material when heating it red hot, but worry this may weaken it in some way, leading to early failure. Rust is only a minor concern as this light will likely be on me most of the time or well taken care of at least.

 

[gadget_lover]

What you need is a quick brush-up on the art of heat treating. There's a specific routine to soften the metal so it can be ground, filed, etc, then another routiine to harden it to the point where it's springy again.

You can pick up small sheets of thin steel at the hobby shop. You can also get it at many hardware stores. Once you cut it, grind it, shape it etc you then heat treat it and.... Bingo, a clip with spring.

You could start with something like a cheap steak knife, but don't count on being able to do sharp bends without it breaking.... unless you heat it first, then you have heat treat it to get it back to springy again (see above ) .

Good luck on your project,

Daniel

 

[LukeA]

What you need is a quick brush-up on the art of heat treating. There's a specific routine to soften the metal so it can be ground, filed, etc, then another routiine to harden it to the point where it's springy again.

You can pick up small sheets of thin steel at the hobby shop. You can also get it at many hardware stores. Once you cut it, grind it, shape it etc you then heat treat it and.... Bingo, a clip with spring.

You could start with something like a cheap steak knife, but don't count on being able to do sharp bends without it breaking.... unless you heat it first, then you have heat treat it to get it back to springy again (see above ) .

Good luck on your project,

Daniel

Heating metal red hot (to nonmagnetic pearlite) and then letting it cool slowly (i.e. not quenching it) anneals it, making it very malleable. This won't weaken it or make it prone to failure. It just removes most of the coherent crystal structure that makes the metal hard and resistant to bending.

IIRC, coating the part in motor oil and burning that off a few times will heat it hot enough but not too hot to return spring temper. Then you'll have to polish/brush it so it isn't hideous looking.

Looking at the design, I would relax the sharper bends for the sake of mechanical strength.

 

[tnuckels]

I did some quick reading over at the wiki and a few other places on heat treating metals, so I follow what you're saying about heat to red hot, then slow cool to make malleable, then reheat to a lower temp to return temper. Good to know there is a shade tree mechanics guide to doing this, as much of what I read had the potential to be quite complex and precise.

Here are the two clips I am "borrowing" ideas from:
ARC 4+/HDS Clip: http://www.lighthound.com/index.asp?PageAction=VIEWPROD&ProdID=2364
McGizmo Clip: http://theledguy.chainreactionweb.com/product_info.php?cPath=48_55&products_id=653

I really like the idea of the "deep pocket" design of the ARC/HDS clip, but as I am unwilling to penetrate the body of the light with screw holes I am confined to the lip at the tail end of the light that houses the recessed split ring. I am further constrained by the fact that I do not want my clip to extend beyond the tail end of the light, adding to its length and preventing it from tail standing. To top it all off, this is a small light, about 0.8"x2.6", and I want the clip to be of a pleasing proportion to the light and not overpowering to look at.

I think I'll try to make one as designed above, but may end up backing off to the much simpler angles and bends like the McGizmo clip in the end.

Thanks so much for the pointers thus far. Any other comments, pro or con, are greatly appreciated.

EDIT: Here's a much simpler design ... perhaps I should crawl before I try and sprint.

 

[indycrucible]

I did some quick reading over at the wiki and a few other places on heat treating metals, so I follow what you're saying about heat to red hot, then slow cool to make malleable, then reheat to a lower temp to return temper. Good to know there is a shade tree mechanics guide to doing this, as much of what I read had the potential to be quite complex and precise.

The proposed heat treatment you outlined will not do what you think it will. Yes, heating to red-hot (austenite) and slow cooling will anneal the material and make it soft enough to form (bend), but subsequently reheating to a lower temperature will relieve stress from the bending operations, but will not return any hardness or strength the to clip. The saw blade is probably a high carbon steel alloy with induction or laser hardened teeth. You could anneal, cut, bend, reheat to bright red hot, quench in brine water, reheat to about 350F for at least 1 hour, then clean all the oxidation off.

The up-side is a very hard and strong clip, the down-side is it will probably distort when you quench it or worse, crack when you quench it.

I think your best bet is a piece of 300 series stainless steel. Reduce the bend radii of your design, bend it and bolt it on.

 

[tnuckels]

This has been an interesting, if brief and incomplete, education in metallurgy, further adding to my respect for the art. However, all I want to do is make a clip for my flashlight, and as romantic as the idea of "TNUCKELS: pseudo-blacksmith" is, I think I'll take what appears to be the consensus advice and bag the saw blade route in favor of stainless steel, as well as opting for the simpler design in terms of bends.

Even the simpler design works out to be fairly complicated, given the crudeness of my software and hand tools. I enjoy making things like this by hand … just so long as they don't look "hand made" in the end, if you know what I mean.

Off to Linens-N-Things to cannibalize some unsuspecting kitchen wares item.

 

[scott.cr]

Off to Linens-N-Things to cannibalize some unsuspecting kitchen wares item.

Don't forget Big Lots!, or whatever the equivalent "99-Cent-Only" store in your area is. (I raided the kitchen section of Pic-N-Save for cheap raw materials through most of my adolescence.)

 

[dstutts]

PM sent

 

[warlord]

Very interesting stuff. Did you consider cannabalizing a moneyclip or a knifeclip or even a clip from a garage door opener? It might be easier to cut down to spec and you may not even have to worry about making all the fancy bends.

 

[tnuckels]

Don't have a money clip … don't have any money … spent it all on flashlights!

I did eye the clips on some inexpensive knives at the HW store, like the recently ubiquitous folding utility blade knife, but figured cheap knife ≈ cheap clip.

I also toyed with the stealing the clip off one of my measuring tapes or the wire clip off the garage door opener, but in the end I bought an inexpensive Oxo Good Grips stainless steel spatula. So far, so good, and I've removed the handle, cut out the thin tip and thick back ends giving me a piece about 3x5" of uniform thickness to work with. I've cut that down into three pieces so that I can make multiple tries if I screw up the first one. I printed out three copies of my design and am trying to decide the best way to accurately transfer the likeness to the metal, either try and etch the metal (may prove difficult on the hard shiny surface) or cut out a sticky likeness and attach it to the metal while I cut out the design.

I'm certainly open to suggestions here …

 

[indycrucible]

I would print the design out on white sticker/label paper, then stick it to the stainless blank you've created. Stick the entire sticker, without cutting it out, to the metal in one big piece. No reason to cut the design out of the sticker, when cutting the stainless, just follow the lines on the sticker that is stuck to the metal.

Typical home metal cutting techniques (sawing, abrasive cutting, grinding, shearing) will remove the sticker right along with the stainless steel (unless you are using electo-discharge or electro-chemical machining, which I doubt).

After all cutting is complete, peel the remainder of the sticker off of your workpiece.

 

[LukeA]

Try 3M spray adhesive. It goes on in a smoother coat if you heat up the can with hot tap water.

 

[tnuckels]

I tried using my favorite Loctite Super Glue Professional to secure the diagrams during the shaping process, but the bond seems susceptible to the heat generated and lost adhesion to the smooth surface. Perhaps a little roughening up with the wire wheel might help. If not, I'll try some labels and/or 3M spray adhesive next.

A couple more thoughts & questions:

1. What would you use to mark the centers of the holes that will be hand drilled through? I've used sharpened dry wall screws in the past and they work fairly well to get me started and prevent the drill bit from walking all over the surface, though I still get a bit of wander even with a good centered start. None of my punches seem up to hard materials like this and leave more of a dent, not the small hole I'm looking for.

2. Would you very lightly score the material at the bends in hopes of getting a straighter and more defined bend?

It's often surprising how much thought and effort can go into such tiny and seemingly simple creations.

Thanks to all for your guidance and suggestions thus far.

 

[LukeA]

I tried using my favorite Loctite Super Glue Professional to secure the diagrams during the shaping process, but the bond seems susceptible to the heat generated and lost adhesion to the smooth surface. Perhaps a little roughening up with the wire wheel might help. If not, I'll try some labels and/or 3M spray adhesive next.

A couple more thoughts & questions:

1. What would you use to mark the centers of the holes that will be hand drilled through? I've used sharpened dry wall screws in the past and they work fairly well to get me started and prevent the drill bit from walking all over the surface, though I still get a bit of wander even with a good centered start. None of my punches seem up to hard materials like this and leave more of a dent, not the small hole I'm looking for.

2. Would you very lightly score the material at the bends in hopes of getting a straighter and more defined bend?

It's often surprising how much thought and effort can go into such tiny and seemingly simple creations.

Thanks to all for your guidance and suggestions thus far.

Get a dedicated center punch and a #1 center drill. I hope you're using a drill press, too.

 

[tnuckels]

Drill Press … Bah! Drill Presses are for (insert your favorite demeaning term HERE), or for those who want to get it right, or crazies who need , what's that thing called again … oh, yeah, accuracy. :nana:

Slowly eking along here, but here are some progress shots:

Paper Mock-Up

Layout On SS Stock

Rough Stock Takes Form

1st Attempt, ¾ View

1st Attempt, Side View

Lots left to do obviously, but I'm not displeased with the result so far.

 

[indycrucible]

Looks great!

 

[dom]

Looks really good.
Think you should drill your holes first.
Use center punch like suggested ,then smallest drill you can use without breaking -up to the correct size drill you need.
Or you could see if you can buy a rivet drill (usually 1/8") as these are much stronger than normal drills and won't wobble as much doing by hand.


What are you using to cut them to rough shape -dremel and cutoff wheel?

EDIT: don't score where the bend is as it couldl weaken and maybe break there.
Also have you thought of using double sided tape for sticking on your drawing? You can get stuff that is thin as sticky tape -a bit of alcohol wipe on the metal surface will stick it well.

Cheers
Dom