Hi. I'm trying to drill into an overshelf made of stainless steel, as commonly used in kitchens. So, I'm drilling sheet, about 1.5mm thick. To do this, today I've bought a DeWalt "industrial cobalt" drill bit of 2.5mm dia "4 times long life" (DT4901). I've only managed to drill two holes and the drill is now blunt and the tip has clearly been subject to quite some heat. So, I'm now baffled as to why my brand-new drill has only managed to drill two holes in stainless steel sheet before becoming unuseable. I did not employ a centre drill, nor lubrication. My immediate thoughts are that I need a much better quality drill. Do I need to buy a better quality drill because I need to drill 18 holes? Please enlighten me. Thanks. Rich
Very disappointed with my "Industrial Cobalt" DeWalt drill purchase
- Thread starter DIYalot
- Start date
Sponsored Links
stainless steel is very hard, my guess is you have drilled with too high a speed and case hardened the stainless making it difficult to drill
drill with slow speed (around 500rpm) and use cutting fluid
dormer A108 drill bit would be a good choice, but quite expensive
or get some cheap ground HSS drill bits, a set of 10 and just replace as they get dull
www.ukdrills.com
TCT is also good for stainless
www.ukdrills.com
drill with slow speed (around 500rpm) and use cutting fluid
dormer A108 drill bit would be a good choice, but quite expensive
or get some cheap ground HSS drill bits, a set of 10 and just replace as they get dull
HSS Ground Drill Bits (Metric)
HSS fully ground drill bits, split point - 135 degrees. For drilling steel, plastic, wood and similar materials. For enhanced performance, check out our HSS titanium coated drill bits.
www.ukdrills.com
TCT is also good for stainless
TCT Drills
Hss ground drill bit with a Tungsten Carbide Tip. Specially designed for drilling stainless steel.
www.ukdrills.com
When I've drilled, I've had the drill at it's maximun RPM which is 2600. Given the size of the drill (2.5mm) I thought I'd require that speed. Apparantly that's possibly the problem in this case. It's difficult to use cutting fluid as it's one of those jobs where getting holes to match is best achieved by using the backing (I'm affixing to the shelves) as a template. And I'm drilling horizontally. I'll just have to try the slower speed, see what gives. EDIT: I tried the second drill, which is not burnt as the first one, but it makes no cut at the slow speed. I need for sure a carbide drill bit it seems. Actually, I might be better off just trying to source a carbide centre drill, with 3mm drill point diameter that will pierce the 1.5mm sheet. Drill should be 3mm dia., not 2.5mm.
Last edited:
Hi. I found UKdrills on Ebay, and bought two 3mm jobber carbide drills. After thinking I'd be better off just buying a centre drill, about half an hour after my order, I sought to cancel the jobber drill order on Ebay, but it was "too late". That really stinks IMHO, it ought to be too late only after items are in fact despatched. Which I am sure is not the case here. Miffed by UKdrills. RichTCT is also good for stainless
TCT Drills
Hss ground drill bit with a Tungsten Carbide Tip. Specially designed for drilling stainless steel.
Sponsored Links
I use UK Drills regularly, and found them to be excellent value for money, and in fact excellent customer service, when an SDS bit arrived a bit wobbly, once.
They are very quick with dispatch......
As to my order with UK Drills: I told them I think it stinks that I could not cancel my order before despatch. However I told them I will take the order and see how the drills perform. I'm only spending £7 odd for two drills, so it's small beer stuff, but it's the principle that matters. If these carbide jobber drills cut the stainless steel well, I'll be sorted. As I say, it did occur to me that a centre drill would be just the job, because I'm only drilling 1.5mm sheet. Also, I am going to contact DeWalt and see what they say about why their drills performed badly. There is no recommended drill speed on the packaging. EDIT: UK Drills could not understand why I could not cancel. In the end they did cancel for me. So, UK Drills came through good.
Last edited:
i contacted Dewalt , but had to escalate high up the organisation because of a product issue - which they did sort out for me, and in the end were very good , but took a while and persistance, that was around 2019
I also contacted them a few years later , regarding quality of some of there drill and multitool bits and didnt get very far with dewalt , in the end FFX as a good will jesture ONLY did offer 5% of next purchase.... SO i do NOT buy any Dewalt accessories now , I tend to go mainly for Bosch drills , which as a DIYer i have found really really good, - for multitool bits and saw blades i tend to exclusively now use saxtonblades https://www.saxtonblades.co.uk/ and there products do tend to last. As i say used as a DIYer
you may find it difficult to get hold of dewalt , I used the complaints form online , and also various emails i found online - I often try an find the CEO ( Donald Allan, Jr 1/7/22 ) and write direct if i'm getting nowhere , Stanley Black & Decker who own dewalt
I also contacted them a few years later , regarding quality of some of there drill and multitool bits and didnt get very far with dewalt , in the end FFX as a good will jesture ONLY did offer 5% of next purchase.... SO i do NOT buy any Dewalt accessories now , I tend to go mainly for Bosch drills , which as a DIYer i have found really really good, - for multitool bits and saw blades i tend to exclusively now use saxtonblades https://www.saxtonblades.co.uk/ and there products do tend to last. As i say used as a DIYer
you may find it difficult to get hold of dewalt , I used the complaints form online , and also various emails i found online - I often try an find the CEO ( Donald Allan, Jr 1/7/22 ) and write direct if i'm getting nowhere , Stanley Black & Decker who own dewalt
Saxton blades customer service is also excellent, in my experience.
- Joined
- 24 May 2016
- Messages
- 3,817
- Reaction score
- 730
- Country
Agree, using rpm of 2600 on stainless is dumber than dumb! Shouldnt need cutting fluid on 1.5mm sheet though.
TCT is also good for stainless
TCT Drills
Hss ground drill bit with a Tungsten Carbide Tip. Specially designed for drilling stainless steel.
I keep some TCT drill bits in my rucksack for those moments when you come across screw heads that need to de drilled out. From memory, they were from UK drills.
Why would there be, machining speed can be found in tables, and is specific to the material you are drilling. SS needs to be drilled slowly, or it work hardens very easily..
I spent about a year working for a lift engineering company when I was 19. We drilled a lot of holes in steel, mainly mild steel but also stainless. We used high speeds (for small drill bits) but I believe that the drill bits were 135 degrees rather than 118.
The following says that 2.5mm (3/32") should be 2,852rpm
And the following says 3,000 rpm (for pillar drills)
I think it might be good to first use a carbide centre drill, then open the hole with a cobalt or carbide jobber drill and use WD40 (although I'm using the hardboard backing I'm affixing to the shelves as a sort of template, which makes using WD40 problemmatical, unless I use the centre drill to simply mark the drilling spot (through the backing), remove the backing, then complete the drilling with the centre drill and after that opening out of the hole with the jobber drill, then affix the backing). Or, just use a 3mm centre drill.
As possibly a final comment, I've just left a review on Screwfix, and I've just noticed a very similar review made 4 years ago concerning stainless steel. The reviewer rates performance as poor as I have done. Given the RPM tables I have taken speed I used (2600 RPM) as not the issue causing poor performance in light of the drill diameter (2.5mm). And I've discounted the non use of cooling fluid.
Last edited:
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
