LadyInBed
Well-known member
{Straight in with the 10 mm, no pilot.}
I wouldn't have drempt of doing that, what is the rational?
I wouldn't have drempt of doing that, what is the rational?
Who makes really tough HSS drill bits?
- Thread starter Greenheart
- Start date
reeac
Well-known member
The best tip that I've received re. drilling S/S is to make sure that you're ALWAYS producing swarf. If the drill bit just skates over the S/S then you'll get nowhere. I also agree that HSS is as good as anything.
sailorman
Well-known member
re read #20
LadyInBed
Well-known member
I agree with you, thats why I ask about not drilling a pilot in #17.
KellysEye
Active member
> I'm drilling 10mm-thick stainless steel.
Use cobalt drills for SS as recommended by a steel fabricator in Trinidad.
Use cobalt drills for SS as recommended by a steel fabricator in Trinidad.
prof pat pending
Well-known member
As I said, depends on the grade
I've seen people with milling machines struggle with some grades of stainless
prof pat pending
Well-known member
I wouldn't pilot drill it, but then I wouldn't try it with a cordless drill. Somehow I think the OP will have little choice here.
Use a drill that has a bigger diameter than the flat tip on the point of your 10mm drill, but don't go too small or you are likely to snap it.
Patience is the key here, take your time, have a number of drill bits to hand, if you start generating heat change bit and move to another hole.
Cutting oil good ... coolant better. It not only lubricates, but transfers the heat away
In a previous life I worked as a machinist in Cryogenics. I spent all day every day cutting stainless
Use a drill that has a bigger diameter than the flat tip on the point of your 10mm drill, but don't go too small or you are likely to snap it.
Patience is the key here, take your time, have a number of drill bits to hand, if you start generating heat change bit and move to another hole.
Cutting oil good ... coolant better. It not only lubricates, but transfers the heat away
In a previous life I worked as a machinist in Cryogenics. I spent all day every day cutting stainless
lw395
Well-known member
The pro's are right, HSS in a pillar drill will do it no problem,
But as an amateur, if you've already work hardened it, you may find that a carbide tile drill, the spade shaped ones, will be a good bet.
For coolant, lots of water. It keeps the work below 100deg C if you keep it wet. Smoking oil is much hotter.
But as an amateur, if you've already work hardened it, you may find that a carbide tile drill, the spade shaped ones, will be a good bet.
For coolant, lots of water. It keeps the work below 100deg C if you keep it wet. Smoking oil is much hotter.
Sailfree
Well-known member
OK I like good tools but also like value for money.
I have a cobalt drill set
I have the drill set sold at SIBS where the guy demonstrates his drill sets by drilling everything including hardened steel and SS in front of you.
The ones I use most are the packs of various size drills sold by Screwfix and made by Erbauer. Work out the individual price of HS drill and they are fantastic value (especially when using small sizes and hand drills with risk of snapping them). Use new ones on SS, used ones on steel and I have been known to relegate them for timber when I haven't got the exact size wood bit. I also have the equivalent SDS set.
Fred drift - just invested in a Festool circular saw and rail - expensive but the best for accurate cutting laminates without chipping (spotted a professional kitchen fitter using one - always note what the professionals use!). Hoping it works cutting teak/hollow veneer when I re-veneer the cabin floor boards as my winter project.
I have a cobalt drill set
I have the drill set sold at SIBS where the guy demonstrates his drill sets by drilling everything including hardened steel and SS in front of you.
The ones I use most are the packs of various size drills sold by Screwfix and made by Erbauer. Work out the individual price of HS drill and they are fantastic value (especially when using small sizes and hand drills with risk of snapping them). Use new ones on SS, used ones on steel and I have been known to relegate them for timber when I haven't got the exact size wood bit. I also have the equivalent SDS set.
Fred drift - just invested in a Festool circular saw and rail - expensive but the best for accurate cutting laminates without chipping (spotted a professional kitchen fitter using one - always note what the professionals use!). Hoping it works cutting teak/hollow veneer when I re-veneer the cabin floor boards as my winter project.
Last edited:
Greenheart
Well-known member
I'm very glad to have asked the question because there's so much experience here. I've never had a pillar drill...along with router and lathe, it's something I'll one day fill a shed or on-board workshop with.
For now, I only have a new Draper 14.4v cordless drill/driver (a big advance on the hand-drill I was using) which certainly allows low turning speed. My initial under-estimate of the required hole diameter was 3mm, and with much patience, cooling-off time and a couple of broken inferior bits, I have now drilled through two sections of 10mm stainless.
So, my approach is really very humble. I'm basically trying to reproduce the spreader-end-caps which'll let me put the mast up without imminent prospect of it coming down again.
Apologies to contributors who were bored by my earlier description of this difficulty. The fact is, no-one makes the bit I need so I'm making it myself.
I determined that a 10mm dia stainless bolt with a square top, could be drilled through (4mm) to house the shroud, and I'll be grinding a slot longways up the bolt to enable the shroud to take its place in the hole without having to be fed through from its bulky end. So this thread might drift sideways to take in angle-grinding of stainless steel, too.
I'll photo the results...hopefully not a gory mess where my hands had been.
For now, I only have a new Draper 14.4v cordless drill/driver (a big advance on the hand-drill I was using) which certainly allows low turning speed. My initial under-estimate of the required hole diameter was 3mm, and with much patience, cooling-off time and a couple of broken inferior bits, I have now drilled through two sections of 10mm stainless.
So, my approach is really very humble. I'm basically trying to reproduce the spreader-end-caps which'll let me put the mast up without imminent prospect of it coming down again.
Apologies to contributors who were bored by my earlier description of this difficulty. The fact is, no-one makes the bit I need so I'm making it myself.
I determined that a 10mm dia stainless bolt with a square top, could be drilled through (4mm) to house the shroud, and I'll be grinding a slot longways up the bolt to enable the shroud to take its place in the hole without having to be fed through from its bulky end. So this thread might drift sideways to take in angle-grinding of stainless steel, too.
I'll photo the results...hopefully not a gory mess where my hands had been.
Greenheart
Well-known member
And...I just broke another cheap Chinese-made 3.5mm. No more of these pieces of crud, I'm only buying carbide ones henceforth. Or other recommendations...
prof pat pending
Well-known member
When you grind your slots use a new wheel, or at least one that has never seen any steel in previous use
Also don't let the material get too hot, if you have any colour on the material surface rework it
Keep everything clean, remove the grinding dust
Also don't let the material get too hot, if you have any colour on the material surface rework it
Keep everything clean, remove the grinding dust
prof pat pending
Well-known member
Be careful with carbide by hand, It's brittle compared to HSS, chips and breaks quite easily.
Having said that it is by far the best material to cut stainless, but really wants a rigid set-up
Greenheart
Well-known member
Thanks; I bought 1mm thick discs in order to be sure not to cut too wide a slot, which might remove too much of the bolt's strength; now I'm concerned that it'll be too narrow. How smart/unwise/lethal will it be to use two x 1mm discs simultaneously, to broaden the slot?
prof pat pending
Well-known member
Cut off wheels ... personally I'd steer very clear of mounting multiple discs
penfold
Well-known member
Very much this; the ~1mm discs are flexible and cutting can set up harmonic waves in them, sandwiching 2 or more together may cause them to interact and destruct.
Look for a disc slightly thinner than the slot you want to cut; 3mm will probably give you a slot nominally 4mm wide.
alahol2
Well-known member
When drilling stainless I will always go for the pillar drill in the club workshop if it is an option. If I have to do it on the boat or elsewhere I try to arrange a lever which I can use to apply pressure to the top of the drill. I've used various Heath Robinson concoctions involving loops of cord, wedges etc to achieve this. The time spent in arranging the lever is more than equalled by the time saved in drilling the hole.
BERT T
New member
If you want a decent drill bit for stainless, then buy these: http://www.wintersdrillbitcity.com/
I have a set which I bought about twenty years ago and they are still going strong.
I have a set which I bought about twenty years ago and they are still going strong.
TQA
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Well it is time to get some better drill bits just broke two today trying to drill 5/32 holes in some thin SS plate.
Guess I need to pay more than $1.79 for a set at Harbor Freight.
Guess I need to pay more than $1.79 for a set at Harbor Freight.
William_H
Well-known member
I'm very glad to have asked the question because there's so much experience here. I've never had a pillar drill...along with router and lathe, it's something I'll one day fill a shed or on-board workshop with.
For now, I only have a new Draper 14.4v cordless drill/driver (a big advance on the hand-drill I was using) which certainly allows low turning speed. My initial under-estimate of the required hole diameter was 3mm, and with much patience, cooling-off time and a couple of broken inferior bits, I have now drilled through two sections of 10mm stainless.
So, my approach is really very humble. I'm basically trying to reproduce the spreader-end-caps which'll let me put the mast up without imminent prospect of it coming down again.
Apologies to contributors who were bored by my earlier description of this difficulty. The fact is, no-one makes the bit I need so I'm making it myself.
I determined that a 10mm dia stainless bolt with a square top, could be drilled through (4mm) to house the shroud, and I'll be grinding a slot longways up the bolt to enable the shroud to take its place in the hole without having to be fed through from its bulky end. So this thread might drift sideways to take in angle-grinding of stainless steel, too.
I'll photo the results...hopefully not a gory mess where my hands had been.
I would say buy a pillar drill now rather than later. Second hand is fine they don't deteriorate very much. I reckon my old pillar drill is my most loved tool of all. It enables you to get that pressure very easily.
As for poster who complained about cheap drills breaking. I suspect that is his handling method. Generally more brittle drills means hearder means better. Again use a pillar drill.
olewill