Chain Filing

Treeaddict

Treehouser
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I was taught that if you drag your file backwards it will dull the teeth. Many people said this and filed accordingly. After seeing this video and doing some further research, I’ll never lift the file from the chain or relinquish the pressure on the back stroke. In fact, it seems to cut faster pressing on both strokes without any additional damage to the file. Interesting….
 

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That was interesting. Not quite sure what to make of it. I wonder what's boosting the performance of the backdragged file?

edit:
I'm a dumbass. The performance was boosted cause it was taking material off on the backstroke. The backdragged files had 5,000 strokes, with half of them being lackluster, but still removing material.
 
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A file is not a scrub brush. The teeth on a file cut in one direction.

also after almost 40 years I heard a tip last month for sharpening saws in a vise that blew me away. Turn the saw upside down before setting the bar in the vise and you can sharpen from the tip end without the saw in your way. I tried it and it works great!
 
I've got way more experience using metalworking files than chainsaw files, but I'm a firm believer in only filing in the proper direction, as has been taught for hundreds of years now. Files are made by a chisel cutting action, formerly done by chisels and now done with chisel machines :lol: if you drag your file on the backstroke you'll be rounding that off rather than keeping the sharp edge. You might get lucky for awhile if it's a very hard file, but soon you'll start chipping teeth and soon it simply won't cut right.
 
Video guy's results don't really reflect that. After 2.5k backdrag only strokes, 2.5k forward only strokes on the same face were virtually the same as an unused file.
 
That was interesting. Not quite sure what to make of it. I wonder what's boosting the performance of the backdragged file? edit: I'm a dumbass. The performance was boosted cause it was taking material off on the backstroke. The backdragged files had 5 said:
Thanks for the video, I didn't watch it all but why the hell would someone take the time to produce that ?
My take is that chainsaw files are relatively cheap...file as you want. I'm square grinding so could care a less 😄😄

Not directed at you John.
 
That's the thing, i don't know him. Working as a fitter and welding pipe you use a file constantly, and I've worn out a few over the years. Fitters are usually super hard on files, they're used to chip slag and dress welds, ream and square pipe cuts and holes, and repair threads on bolts and pipes. We use half round double cut bastard files, which are about the most aggressive ones you can get because it's rough large material removal work. We're using grinders and stuff obviously, but a file can fine tune stuff far easier since it's lighter and taking less off so you are less likely to overshoot. Different types of files are used for finer and finer work, so each one is designed for a certain rate of removal and the finish it leaves.

Once upon a time people commonly worked metal completely by hand, first with chisels and saws, then with files, then scrapers, then lapping. Over time, they came up with what works and rules for doing stuff a certain way, for example only cutting forward. It seems dumb yes, but by cuting forward you are doing your best to protect the cutting edge. When you're in soft material it doesn't matter, but what happens when you hit something harder, say a chunk of welding slag? The slag is like glass, and harder than the file. Drag it backwards and your new file is now trash.

So stay away from welding slag and you're fine right? Not exactly, and chainsaw chain is a great example. It's very high carbon steel, hardened and tempered. What that means on a metallurgical level is some very hard steel is dispersed in a putty of softer steel, which means your file will be hitting those hard parts which are buried in the soft part. Basically like an iceberg, most of the chunk under the surface, but with a huge tensile strength. Used in a forward direction the teeth will skate, backwards they chip. If you're filing soft stuff no problem, but in different materials you'll hit stuff. Another example is cast materials, they have sand in their outer layers, which is way harder than the file. So if you only file foward you're good no matter what you're working on, so that's the way it's taught.

This ability to slide undamaged over harder materials is used when you make a filing jig, aka a poor mans milling machine. Grade 8 bolts are super hard, and so files don't cut them hardly at all, they just glide over the surface. So you use the bolts as you would concrete forms, basically as a screed height for the file. Once it's sliding on both points you're flat across between the 2 bolts. By knowing the threads per inch and number of turns you can predictably move the stops precise distances, helping make sure you don't go too deep. Roller bearings are the next step up on this technique, with even less file wear, but the bolts work fine today as they did 100 years ago.
 
My favorite file story is still:
At my bicycle shop one day Bob Owens, affectionately called “Snake” was visiting. Snake was a welder-Fitter at the Philadelphia Shipyards. As it happened I was admonishing one of my mechanics for loading up one of our nicest files with soft aluminum instead of using the open-burr Dremel we had for the purpose.

He asked, “What kind of file do you use for aluminum?”
Snake’s answer came a split second before the question mark registered at the end of the kid’s question: “Someone else’s!”
 
I've found that chain files I've deemed not good anymore and relegated to bench use are sharper than my ok to use workbench files. Apparently different standards or expectations of performance might be occurring. I was taught by a machinist forward only.
 
Smaller teeth and harder to cut the hardened chain. By being a bit softer the larger files can have some toughness to survive handling (they don't have much), and are that way because the larger section quenches slower. A bunch of ours at work have been used for an arm rest while welding, so they are all covered in berries, soft and worn down on the edges, where welders use them. A couple even have a sawsall blade tacked on in a desperate attempt to remove slag cause they are fighting it and don't trust their ability to burn out a bit of slag.

Needless to say i carry my own, use the corners by the tang for chipping slag to save the edges, which are used to church up your sides. By gently filing the pipe along an edge of a weld it gives it a straight line on the side of your weld, and taken to a slight extreme can make very slight undercut disappear. This can also remove slag slightly trapped at the toes of weld, which is where 7018 traps at since the puddles so big. With 6010 i simply grab a few rods and scrape them over it, and know that I'm gonna run smoking hot and carry enough metal to know that I'm gonna burn the rest out since it's a light slag. Hard life for a file, the only easy job they ever get is sharpening soapstone (only way to go). They also are often used in the ubiquitous tie wire turnbuckle :lol:
 
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