Metal Drilling Guide | HSS vs. TiN v.s Cobalt Drill Bits | Our Dormer and Alpen Drill Bit Range

Metal Drilling Guide | HSS vs. TiN v.s Cobalt Drill Bits | Our Dormer and Alpen Drill Bit Range

Here’s our guide for choosing the correct drill bit when drilling into metal, including the pros and cons of each type. We’ve also included some top tips on how to drill into metal effectively.

When browsing our site, you’ll see that we only sell the Dormer and Alpen drill bits. This is because we believe that quality matters. Both of these brands are respected by professionals and DIY enthusiast for their superior quality, performance and longevity compared to others available in the market.

Which metal drill bit do I need?

Metal drill bits come in two main types, High-Speed Steel (HSS) and Cobalt. You should never use Carbon-Steel bits on metal, they will blunt quickly or snap under the pressure. HSS and Cobalt each have their own pro’s and con’s which we’ve listed below.


HSS Jobber Drill Bits – Engineered for General Purpose Use

HSS Jobber Drill Bits – Engineered for General Purpose Use-JAR UK Industries

Recommended for: Occasional day-to-day use on softer metals and materials. Should be considered disposable when compared to TiN and Cobalt drill bits.

Suitable for: mild steel, iron, copper, aluminium, magnesium, wood and plastic

  • Designed for general purpose and occasional use
  • Lowest cost choice for metal drilling
  • Can be sharpened using a bench grinder
  • Not suitable for hardened steel, alloys or stainless steel (See Cobalt below)
  • Should be used at slower speeds to reduce heat build up (which dulls the drill bit faster)

View our HSS Jobber Twist Range:


Dormer HSS Jobber Twist A100 Metric



Dormer HSS Jobber Twist A100 Imperial


Alpen HSS Jobber Twist Sprint Metric


Alpen HSS Jobber Twist Sprint Imperial


Dormer HSS A100 Set – 19 Pieces

Dormer HSS A100 Set – 25 Pieces

Alpen HSS Sprint – 19 Pieces

Alpen HSS Sprint – 25 Pieces


HSS Titanium Nitride (TiN) Coated Drill Bits – Engineered for an Extended Life

HSS Titanium Nitride (TiN) Coated Drill Bits – Engineered for an Extended Life

Recommended for: Regular use by professionals or DIY enthusiasts looking for a longer lasting metal drill bit that won’t break the bank.

Suitable for: mild steel, iron, copper, magnesium, wood and plastic (not recommended for aluminium)

  • Feature a ceramic thermal coating designed to reduce friction (and therefore heat), which means the drill bit can stay sharper up to 6 times longer than normal HSS drill bits
  • Can be run faster (40-60%) and harder (10-20% greater feed) than uncoated drill bits
  • Can be used (occasionally) on some tougher metals if used with care
  • Can be used in metal cutting machines (Pillar or bench drill, CNC machines, Lathes etc.)
  • Cost effective and will outperform standard HSS bits during their operating life
  • Cannot be sharpened without removing the TiN coating
  • It’s best not to use these with aluminium as the coating can sometimes end up welded to the metal

View our TiN Range:

Dormer HSS TiN A002 - Metric - jar uk industries

Dormer HSS TiN A002 - Metric

Dormer HSS TiN A002 - Imperial jar uk industries

Dormer HSS TiN A002 - Imperial

Dormer HSS TiN A002 Kit – 19 Pieces

Dormer HSS TiN A002 Kit – 25 Pieces


Cobalt (HSCo) Drill Bits – Engineered for Hardened Metals

Cobalt (HSCo) Drill Bits – Engineered for Hardened Metals jar uk industries

Recommended for: Regular use on hard metals and stainless steel, or those looking to invest in drill bits that will stand the test of time.

Suitable for: hardened steel, alloys, stainless steel, cast iron and titanium

  • Made from a steel-cobalt alloy that contains between 5% (Alpen) and 8% (Dormer) cobalt metal
  • Superior durability compared to standard HSS drill bits. Very heat resistant and will drill through tougher materials quickly without blunting as quickly
  • Can be used on softer metals equally as well as standard HSS. We don’t recommended they are used regularly on wood or plastics (use a cheaper drill bit instead)
  • Can be used in metal cutting machines (drill presses, CNCs, Lathes etc.)
  • Can be sharpened multiple times extending the life of the drill bit
  • More expensive that HSS drill bits, but this is offset by an extended working life
  • More brittle than HSS, so care should be taken when used

View our Cobalt Range:


Dormer HSS Jobber Twist Drills A777 8% Cobalt

Alpen HSS Jobber Twist Drills 5% Cobalt

Dormer Cobalt Spot Weld

Alpen HSS Cobalt Spot Weld

Alpen HSS Cobalt TiN Coated jar uk industries

Alpen HSS Cobalt TiN Coated

Alpen Cobalt Kit – 19 Pieces

Alpen Cobalt Kit – 25 Pieces

Alpen Cobalt Kit – 25 Pieces

Alpen Cobalt Stub Drill Set jar uk industries

Alpen Cobalt Stub Drill Set

Which Brand should I buy? Dormer Vs. Alpen

Dormer: Top quality drill bits for professionals and DIY enthusiasts that want the best money can buy. Our range includes A100 steam tempered general purpose drill bits, A777 TiN tipped professional range and an 8% cobalt content in the A777 range.

View our Dormer Drill Bit Range

Alpen: Professional drill bits manufactured in Austria and which are a more cost effective choice over Dormer. Their cobalt drills feature a 5% cobalt alloy content and we have a wider range of sizes available in the cobalt range.

View our Alpen Drill Bit Range

How to Drill into Metal – Our Top Tips

When it comes to drilling holes in metal, there are different techniques you can use to do it quickly, effectively and safely. It goes without saying, that we’d always recommend using safety googles and gloves whenever you drill into metal.

Here are some of our top tips to get the perfect hole every time:

Always use an oil or lubricant when drilling metal

Heat kills drill bits, so lubricate (and always on stainless steel). The heat generated when drilling is what blunts drill bits quickly so it’s important to keep this under control. Use a cutting fluid (e.g. our SAS Cutting Oil) to reduce the build-up. Using the correct oil lubricates the drill bit and metal that are in contact with each other, without impacting on the friction needed to cut through the material effectively.

NB: If you’re drilling a small hole through a thin piece of soft metal (e.g. aluminium or brass) then a multi-purpose lube will be fine.

Clamp Down the Metal

If you’re not using a pillar drill and the metal isn’t secure, then we always recommend clamping the metal piece down to a work bench with a couple of clamps. This stops the metal from vibrating and the drill bit from catching in the metal which will cause it to spin, strike and slash, which can ruin the hole or worse still, cause an injury.

Mark the Drilling Points with a Centre Punch

If you have one available, its best to use a centre punch to create a small indentation in the metal before drilling. This will give the point of the drill bit a place to sit in, acting as a guide for the drill bit so it doesn’t move or skid across the metal when you start to drill.

If you don’t have a centre punch, then for occasional jobs, a screw or nail tapped with a hammer can be used in place of a centre punch.

Drill a pilot hole

A pilot hole puts less pressure on the metal and drill bit, allowing you to drill larger holes easier than doing it from cold. 

If you’re drilling a hole larger than 4mm, its normally worth doing a pilot hole. Use the rule of doubling up for simplicity. For example if you want to drill a 6mm hole, drill a 3mm pilot hole. If you’re drilling bigger hole, e.g. 12mm, then it’s normally better to work in a three step increment, e.g. drill a 4mm pilot hole, then 8mm then 12mm.

What drill speed to use when drilling metal

This isn’t a hard and fast guide as it will vary between the drill bit type and size, metal thickness and metal type, however generally speaking different metals should be drilled at different rpm speeds to control heat build-up, extend the life of the drill bit and to ensure a clean hole. Here’s a guide for the most common metal types:

  • Steel and Stainless Steel - Low, around 300-400rpm
  • Copper - Low, around 300-400rpm
  • Aluminium - High, around 1500rpm
  • Mild Steel - Medium, around 700-100rpm
  • Cast Iron – Low, around 200-300rpm

A good rule of thumb is to always start slowly until the drill bit cuts into the metal before increasing the speed. Stop drilling occasionally and top up on lubricant as needed. If the metal starts to squeal, smoke or discolour when drilling then you’re going too fast. Slow down (and lubricate)!

How to drill a countersink and deburr the edges

If you need to insert a countersunk screw into the hole that you’ve drilled, then you’ll need to use a HSS countersunk drill bit. These will create the necessary recess for the head of the screw to sit flush with the metal. Ensure you drill very slowly and perpendicular (at a 90 degree angle) to ensure a clean finish.

Countersink drill bits come with the added advantage of deburring the edges. If you don’t need a countersink, then the easiest way to deburr an edge is to put a slightly larger drill bit into the hole you’ve drilled and twist it so that the flutes of the larger drill bit bite into the burrs and lift them off.

How to drill into sheet metal and thin metal

If you regularly drill into thin or sheet metal, or need to drill multiple holes, we’d recommend using a step drill. They are engineered to drill into this metal type with ease, and will provide a smooth round hole.

Remember to drill on a flat surface (a piece of unwanted wood for example), to prevent the metal from deforming or bending when you begin applying pressure.

Take a look at our HSS Step Drills here.

Anything we’ve missed?

Let us know in the comments section below.

About JAR UK Industries

JAR UK Industries is a family run workshop consumables and automotive supplies specialist based in Maidstone, Kent, UK. Our goal is to provide quality products and brands that are competitively priced. We provide personal customer service to both the trade and public. We supply a range of workshop essentials including workshop assortments, bulbs, auto electrical supplies, welding, abrasives, cutting and drilling, fasteners and fixings and more.  You can read more about us here

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