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Can you cut Titanium screws to size?

Old 11-16-20, 12:59 PM
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vane171
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Can you cut Titanium screws to size?

Hi, I would like to replace screws on my handlebars, they are black with conical head. I think I need M6x20 but it seems I can only buy M6x30, 30 mm long. Can you cut titanium screws to shorten them? Never worked with this metal before.

I found these screws on Amazon
https://www.amazon.ca/Wanyifa-Titani...401025&sr=8-37

They sell shorter ones in M5 size but I 'think' (because I didn't want to undo my screws before having new ones in hand) all my screws on the bars are M6 since they all fit 5mm Allen wrench. And I can measure the diameter of the thread in the stem where there is gap enough to see the screw body and that is 6mm. You'd think naively that M6 would use 6mm Allen hex but that's likely due to my having little experience with this type of screws.

Last edited by vane171; 11-16-20 at 01:05 PM.
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Old 11-16-20, 01:04 PM
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Yes, you can. Dremel at high speed using fibre reinforced cutting wheel Put the proper size nut on the bolt befor cutting, then roll the nut off after cutting to ensure a clean entry thread.
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Old 11-16-20, 01:37 PM
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Normal hacksaw then won't do? I have 3.5" Aluminum Oxide cutoff wheels on my bigger Dremel hand held saw which is bigger than what you have in mind, I believe those 1" or thereabouts small wheels that spin at high rpms. But the issue might be the disk material perhaps? Just checked and my bigger saw spins at 13k rpm max, so that should be OK. Just the Al Oxide is the most common cut off wheel material I suppose but it should do?

BTW is my guess right that if 5mm Allen wrench fits all the heads of the screws, then they will all be M6?

The bike in question is 2007 Trek with aero handlebars, four screws in stem.and four that hold the aero bars. I plan to ship the bike by air and I figured out if I have to undo these old screws (I really have to unscrew just two on the head tube), I might as well replace them all since they rust a little on the heads where the wrench damaged the paint finish on them. If they rust, I suppose that means they are not titanium, just some grade of steel. Anyway, even if didn't intend to replace them, it will be safer to have replacement on hand when I do unscrew them.

Last edited by vane171; 11-16-20 at 01:48 PM.
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Old 11-16-20, 03:39 PM
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You can cut them OK with a Dremel, as mentioned. However, for this application I'd rather use some decent high-grade steel fasteners than some Ti screws of unknown provenance
Note also that M6 fasteners come in coarse (1mm pitch) and fine (0.75mm pitch) thread - make sure you're getting the right one
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Old 11-16-20, 05:03 PM
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Originally Posted by Litespud
... However, for this application I'd rather use some decent high-grade steel fasteners than some Ti screws of unknown provenance
Note also that M6 fasteners come in coarse (1mm pitch) and fine (0.75mm pitch) thread - make sure you're getting the right one
Somehow I thought Ti is not just light but also strong, or it may just be that quality grade (the provenance). I suppose here like with most everything, you get what you pay for, some screws are quite expensive. Maybe steel (stainless steel?) would be better, I can put some black paint on the heads once screwed in.

Coarse/fine threads, thanks... I think these will be fine ones, the machine screws. I suppose there is nothing to it but I will have to unscrew some of them to test the thread in nuts (or in template like some shops have to help folks like me), my experience doesn't quite stretch too far in this direction. I grew up in EU and have constant struggle with the many screw types in North America, it is a constant headache.

I'd say, bikes are all metric, so it should be fine thread. But the Amazon seller says nothing about the thread pitch on those particular screws I found, see the link above (there the thread looks to be coarse). There is very little choice with those conical heads.

Last edited by vane171; 11-16-20 at 05:09 PM.
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Old 11-16-20, 05:11 PM
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If you look further down at the Amazon link you referenced, the bolts are also available in 20 mm length with either blue or grey heads.
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Old 11-16-20, 05:17 PM
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Originally Posted by vane171
I found these screws on Amazon
With titanium prices dropping, the temptation to replace screws with lighter titanium is high.
But bare in mind, titanium screws are also graded (rated) for strength, at least the good ones from reputable sources are.

Replacing mission critical screws on a bike with Amazon specials might not be the best idea.
Bottle cages... sure, if you must.... Stem, not so much.

I'm sure 9/10 people may claim it works just fine.

Pays your money, takes your choice.

All the best

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Old 11-16-20, 05:35 PM
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I have enough fasteners of known size knocking around the garage these days that I can easily determine the specs of an unknown, but I used to use the templates in Lowes or the Home Despot all the time - super useful. That being said, if you have a millimeter ruler, just measure the distance across 11 peaks/10 grooves - it'll be 10mm or 7.5mm. There'll be no confusing it. If you go to a bona fide fastener supplier like McMaster Carr or Fastenal, you'll find the real thing - strong black oxide-coated alloy steel screws with the tensile strength of 6/4 Ti, but with loads of options re sizes etc, and full specs, so you'll know exactly what you're getting.
Back when I used a 2-bolt stem that came with Ti (M5) fasteners, responding to anecdotal stories of small Ti fasteners breaking (and on a 2-bolt stem, you really couldn't afford to have one of these bolts fail), I replaced all the fasteners with black oxide screws. Over years they developed a slight surface rust, but it was easily removed with a Q-tip dipped in isopropanol
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Old 11-16-20, 07:57 PM
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And as to whether you can cut ti with a standard hacksaw? Although I've not tried, ti is not particularly hard so my guess it would be no match for the hardness of a hacksaw blade. Perhaps it would dull the blade quicker than mild steel but it would still cut. Screws tend to be tough (ie they can handle bending/stretching) and not super hard as that would make them too brittle and thus suffer from catastrophic failure.
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Old 11-16-20, 08:00 PM
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The yield strength for Ti is generally less than half of that for steel. That is, for the same size screw, steel is much stronger. If the bike was designed and fasteners were sized assuming steel screws and bolts, and you substitute Ti, you are weakening the design. It may have enough spare designed in, maybe not.

Ti also galls something terrible. Not so bad if you use Ti in a steel threaded hole or steel nut, but using a Ti bolt and nut is asking for trouble unless you have special prep (e.g. silver plated bolt, or scrupulous application of anti-gall compound).

Litespud's approach - swapping steel for Ti - seems to be to be a much better idea than vice versa.
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Old 11-16-20, 08:04 PM
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Titanium work-hardens. So slow and plenty of pressure (not getting it hot), while applying cooling oil liberally is usually the recommendation for drilling/cutting in titanium.

That said, I cut down my ti handlebars with a hacksaw. No problem whatsoever. A hacksaw will also easily do your thin bolts.
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Old 11-17-20, 02:03 AM
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Thanks all, I will go with steel then since I am not chasing grams here. But they got to be black or if not, then the color of bare metal (those screws in other colors as HillRider suggests are no option unless I would paint the screw heads black). The other limitation is conical heads. They just look right on these bars.

I'd have thought, when it is not some obscure brand but Trek, which is Bontrager bars, the thread pitch of the screws would be given and it would be the same as on all other major brands and really the same all over the bike(s), not just on the bars and there would be no doubt which it is.

I would always try hacksaw first because cutting wheels can overheat the metal fast and that can't be good for them. The screws I have seem to be coated with something like plastic or it might be some baked enamel, I guess what is being sold these days is anodized and should be more resistant to getting scuffed by Allen key and subsequently rust.

I may end up unscrewing them and use rust remover and touch them up with black paint since they are not that badly rusted, just a touch of rust where Allen key scuffed them a little when they were tightened over a decade ago. I just thought if I have to unscrew some to take the bars off for shipping, I might as well replace them. But it is turning up to be quite involved thing.

It is not the cutting to size that bothers me, I am quite mechanically skilled and I cut screws number of times here and there, just never handled Titanium metal. I only know that it is light for its strength and it can handle high temperatures, like in aerospace applications.

Last edited by vane171; 11-20-20 at 04:59 PM.
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