Jobber / Twist Drills

Jobber Drill Bits Explored

Jobber drills are a type of drill bit commonly used for general-purpose drilling. Consequently, they have a standard length, usually around 8-12 times the diameter of the bit, which gives them a good reach and makes them ideal for many applications. This makes them suitable for drilling into various materials like metal, wood, and plastic.

Jobber drills are also known for their ability to give you a good balance between strength and flexibility - making them a popular choice in workshops, especially for tasks that don’t require very deep holes or specialised drill bit designs.

What Are Jobber Drill Bits?

Jobber drill bits such as the Dormer HSS, or the Dormer A100 HSS>, are among the most commonly used power tool accessories in various applications - from household DIY tasks to professional construction work.

This is due to them being well known for their standard length and moderate length-to-diameter ratio - which makes them ideal for drilling holes through materials like wood, metal, and plastic easily as a result.

So, whether you are working with stainless steel, alloy steel, non-ferrous metals, cast iron, or mild steel, jobber drill bits are really designed to deliver high-quality results.

History of Jobber Drill Bits

The term "Jobber" originated in the manufacturing world, where these bits were developed to suit a wide range of tasks - or "jobs" - making them invaluable for day-to-day work on the whole.

The jobber drill bit's design has then adapted over time, evolving with advancements in material science and manufacturing techniques that have come out since.

This is especially true with the introduction of materials like High-Speed Steel Drill Bits (HSS) and cobalt alloys, as well as coatings like black oxide and Titanium Nitride (HSS TiN) for example. As a result, jobber drill bits have become even more efficient and durable due to the properties these bring.

Application Uses for Jobber Drills

As a result, these types of drill bits are ideally suited for many applications, with some of these being:

Metalworking

Here, Jobber drills are commonly used in metalworking to create clean and precise holes in various metals, including steel, aluminium, and brass.

Woodworking

In woodworking, jobber drills are also ideal for drilling holes in wood, offering you a lot of use cases across different types of wood and thicknesses as a result.

Plastic Fabrication

Jobber drills are also very effective in drilling through plastics - making them useful in the production of plastic components and parts.

Construction and Carpentry

Carpenters and builders also use jobber drills for a wide range of tasks, from framing and assembly to installing fixtures, to name a few.

Electrical Work

Electricians will also often use jobber drills as well to drill holes for wiring, conduit, and other electrical installations.

Automotive Repair

Jobber drills are also a key tool in automotive repair shops for drilling holes in metal parts - such as engine components or body panels, for example.

HVAC Installation

Jobber drills are also very helpful in HVAC work for creating holes for ductwork, pipes, and other system components.

Plumbing

Plumbers then use jobber drills to drill holes in walls, pipes, and other materials to accommodate piping and fittings.

DIY and Home Improvement

Jobber drills are also very popular for home improvement projects, from furniture assembly to installing shelves and cabinets as well.

Jewellery Making

In jewellery making, jobber drills can be used to create precise holes in metals and stones - contributing to the fine detail work here.

Structure of a Jobber Drill Bit

A typical jobber twist drill bit has a few key parts, which can consist of, for instance,

Shank Drill

This is the end of the drill bit that fits into the drill chuck.

Cutting Diameter

The cutting diameter of a jobber drill then determines the size of the hole it creates.

It is also essential to choose the correct diameter for each job to ensure that you get the precision you need.

For instance, here, a consistent cutting diameter helps you avoid wobbling and uneven drilling, making it easier to achieve clean, accurate holes - especially when working with metals and hard materials.

Cooling – Coolant Through

Coolant-through jobber drills also allow metalworking coolant to flow directly through the bit, keeping it cool during drilling.

As a result, this feature reduces heat build-up, which can lead to damage to both the drill and the material if left to build up.

Consequently, effective cooling will also extend the bit’s life while also improving your accuracy and allowing for smoother drilling in tough materials, like metals, by minimising the bit's wear as a result as well.

Cooling – T/Coolant

T-coolant - or external cooling helps prevent overheating in jobber drills, especially when drilling for extended periods.

By applying coolant externally to the drill and work area, the risk of frictional heat damage is also directly reduced. Consequently, this cooling method is ideal for materials sensitive to heat, helping to maintain the integrity and quality of drilled holes as a result.

Tip with Point Type

The point type of a jobber drill, such as split or standard, then affects how it cuts into materials.

A split point, for example, improves your control while also reducing walking on harder surfaces - allowing for more precise starts as an end result.

Different point types then suit different materials and applications, making this feature really key for accuracy and reducing your drill bit wear as it does so.

Flute Length

The Flute length then determines how quickly chips (debris from drilling) are removed from the hole that is being created.

For instance, here, you want to make sure that your Jobber drills have an appropriate flute length to allow faster drilling, as this will help to reduce clogging and increase your efficiency as a result.

Consequently, choosing the correct flute length for the material and hole depth you are working on and want to achieve will also help you prevent a bit of overheating and improve your overall performance at the same time - especially in deep or thick materials.

Overall Length

The overall length of a jobber drill will also affect both its reach and rigidity.

For instance, longer bits provide greater reach, which is essential for drilling deeper holes, while shorter bits offer you more control and stability.

Consequently, choosing the right length really is key as it ensures you have sufficient reach without sacrificing precision - making it easier to handle various materials and depths effectively.

Body Length

This bit's body length then refers to the distance from the drill’s cutting edge to its shank.

This value will then impact both your flexibility and strength. For instance, a longer body is more suited to deeper holes, and shorter bodies are ideal for tougher materials.

As a result, selecting the correct body length here will help to ensure that you get the stability you need during drilling - reducing the chance of bending or breakage, which can damage both the bit and material if it occurs.

Why Does a Jobber Drill Series Matter?

A jobber drill series refers to a specific group - or line - of jobber drill bits that share particular design features, performance characteristics, or intended applications.

For instance, each series is typically designed to meet certain drilling needs, such as different material types, cooling requirements, or hole depths, and may vary in length, diameter, point type, or flute design, for example, to achieve this.

As a result, some series might be optimised for high-speed drilling in metals, while others may be designed to handle softer materials like wood or plastic.

By having multiple series, you have more targeted options to choose from when needed, making it easier to choose the right drill bit for a specific job.

Each series will generally have a unique code (like A100 or 208) that helps you identify the particular strengths and applications of that series quickly.

For instance, these are:

Types of Jobber Drills

The composition of a jobber drill bit will also impact its durability and suitability for various tasks.

For instance, this is due to:

TiN Coated Jobber Drill Bits

Titanium Nitride coating increases wear resistance and durability, making it suitable for high-performance drilling.

Black Oxide Coated Bits

These can then give you good corrosion resistance and reduced friction for smoother drilling.

Cobalt

Cobalt jobber drills and Cobalt Jobber Drill Bit Sets are then made with a blend of cobalt alloy, providing excellent heat resistance and durability.

As a result, they are ideal for drilling hard materials like stainless steel and cast iron, as the cobalt improves its wear resistance, extending the bit's life even under high-speed applications.

HSS (High-Speed Steel)

HSS jobber drills are then very adaptable and affordable, making them ideal for general-purpose drilling in wood, metal, and plastic.

Known for their durability and high-speed performance here, HSS bits are often the go-to choice for every day drilling tasks, as well as medium-strength materials.

HSS-Cobalt

HSS-Cobalt drills then combine the flexibility of high-speed steel with added cobalt for improved heat resistance.

As a result, this makes them a great choice for drilling into harder metals, providing both longevity and reliable cutting efficiency as they do so for more demanding applications.

HSS-Co

HSS-Co jobber drills then offer you a specific blend of high-speed steel with cobalt, improving their toughness and reducing their wear during high-temperature drilling.

Consequently, these are particularly useful for applications requiring repeated drilling through hard materials like stainless steel and alloys as a result.

HSS-E

HSS-E jobber drills then feature high-speed steel, which is improved with additional elements for improved heat tolerance and durability.

This, then, in turn, makes them ideal for high-precision and long-duration drilling tasks, as they perform well in applications where strength and reliability really are crucial.

HSS-E-PM

HSS-E-PM (Powder Metallurgy) drills then offer you enhanced durability, toughness, and precision thanks to their fine-grain structure.

For instance, these are well suited for precision work in tougher materials and provide you with superior resistance to wear during prolonged use as well.

HSS-EX

HSS-EX drills are then crafted for extreme conditions, and offer you exceptional heat and wear resistance as a result.

Consequently, these are perfect for high-performance drilling applications in the aerospace and automotive industries, where reliability under stress is more than essential.

HSS-HM

HSS-HM (High-Speed Steel-Hard Metal) jobber drills are then drill bits that are reinforced with hard metals, making them ideal for very hard materials and reducing the need for frequent replacements.

Consequently, they are excellent for heavy-duty drilling tasks, as they offer you extended tool life in challenging environments as a result.

HSSCo 5

HSSCo 5 jobber drills contain 5% cobalt, making them more resistant to heat and wear. This composition allows them to perform well in tough materials like stainless steel, improving efficiency and tool lifespan in demanding settings.

HSSCo 8

HSSCo 8 drills, with 8% cobalt, then offer you even greater durability and heat resistance.

As a result, these are suited for heavy-duty drilling in extremely hard materials, such as hardened steel and alloys, and are often used in industrial environments requiring reliable performance as a result.

M42 Cobalt

M42 Cobalt drills, with around 8% cobalt content, are extremely hard and can withstand high temperatures.

These bits are then commonly used for drilling stainless steel, titanium, and other high-strength metals, providing you with excellent wear resistance and longevity under tough conditions as a result.

Solid Carbide

Solid Carbide drills are then extremely hard and brittle, making them well suited for drilling very tough materials like ceramics and composites as a result.

This is due to them maintaining their sharpness over long periods, making them ideal for high-speed, precision drilling - particularly in industrial applications requiring ultra-hard materials as well.

Standard Sizes and Measurements

Jobber drill bits also come in both metric and imperial measurements, and their range of sizes is standardised for most general drilling tasks as well. This then gives you plenty of depth without compromising your stability as a result.

They also range from very small sizes, ideal for precision drilling, to larger diameters for creating holes in thicker materials as well.

Types of Jobber Drill Bits

Jobber drills also come in varying types as well as varying material compositions.

Some of the most common ones, for instance, consist of the following:

Twist Jobber Drill Bits

These are the most common types you will find and are suitable for a wide range of materials and applications.

Split-Point Jobber Bits

These feature a more modified tip for easier starting, which prevents the bit from "walking" on hard surfaces like stainless steel and cast iron, for example.

Parabolic Flute Bits

These are also designed for rapid removal of material, which is useful in deep hole drilling and soft materials, for instance.

Jobber Drill Bits vs. Other Types

Compared to stub drill bits, which are shorter, and extended-length bits, which are longer, jobber drill bits offer you a great balance between reach and control.

As a result, this middle-ground length is why jobber drill bits are often the default choice for drilling tasks - providing you with excellent hole quality without sacrificing stability as they do so.

How to Choose the Right Jobber Drill Bit

When selecting a jobber drill bit, some of the key points for you to consider consist of, for instance:

Material

HSS Jobber Drill Bits fare or soft materials, and cobalt Jobber Drill Bits fare better or harder metals.

Size

Choose according to the diameter and depth of the hole needed. A jobber drill set with a range of sizes can be very handy.

Point Angle

118° is ideal for many applications, while 135° is better for harder materials like stainless steel and cast iron.

Coatings

TiN Coated Jobber Drills and black oxide coatings here, for instance, will give you great durability and performance. For how these differ, we have a more in-depth section above.

Maintenance and Care

To keep jobber drills in top condition, you should then clean them regularly by removing debris after each use - as this will help maintain your hole quality.

Then, where possible to do so, you should also consider sharpening the tip when needed to reduce friction and improve their overall performance as well - especially during high-performance drilling applications.

Finally, you also want to lubricate them when in use and when drilling hard metals to prevent overheating and extend the bit's lifespan as well.

As a result, you should replace your drill bits a lot less often.

Safety Tips When Using Jobber Drill Bits

Wear Protective Gear: Goggles and gloves are essential.

Secure the Workpiece: Use a clamp to prevent movement during drilling.

Use Proper Speed: Slower speeds for metals like stainless steel and cast iron, faster for wood and plastics.

Check the Drill: Ensure your power is in good condition and compatible with the bit's shank size.

Common Mistakes to Avoid

When using jobber drills, always wear personal protective equipment like goggles and gloves for safety.

You also want to secure the workpiece with a clamp to prevent any movement during drilling.

You also want to use the proper speed, as choosing slower speeds for metals like stainless steel and cast iron and faster speeds for materials like wood and plastics will give you better results. Then, finally, check that your drill is in good condition and compatible with the bit's shank size for optimal performance and safety as well.

Can a jobber drill bits drill through hardened steel?

Cobalt Jobber Drill Bits or carbide-tipped bits are recommended for hardened steel to withstand the material's hardness and maintain hole quality.

How Do I Sharpen a Jobber Drill Bit?

You can use a bench grinder or a sharpening tool to maintain a sharp edge on the tip, as keeping the correct point angle really is key here for optimal performance.

Are Jobber Drill Bits Rust-resistant?

HSS bits can rust if not stored properly; however, coated bits like TiN TiN-coated jobber Drills or black oxide bits have added rust resistance though.

What Does "118-degree tip" Mean on a Jobber Drill Bit?

This refers to the point angle of the tip; for example, a 118-degree tip is used for many applications, while a 135-degree tip is better for harder surfaces like stainless steel.

How Long Do Jobber Drill Bits Last?

The lifespan depends on the material and frequency of use, but with proper care, they can last through many drilling tasks.

Especially if you consider using the appropriate bit for the material, such as an HSS Drill Bit for wood or a cobalt drill for stainless steel, as these will extend the life of the bit as well.

Jobber Drill Bits Final Thoughts?

As you can see, Jobber drill bits are really the go-to tool for various applications thanks to their efficient drilling of various materials and projects.

This is due in part to their balanced design, which makes them indispensable, as they combine durability, precision, and cost-effectiveness for professionals and DIY enthusiasts alike.

As a result, by selecting the right type — whether it is an HSS Jobber Drill Bit, a Cobalt Jobber Drill Bit, or a TiN Coated Jobber Drill — and maintaining it well, you can maximise the benefits and lifespan of your jobber drill bits really easily.

So do not hesitate to explore related products and set up a trade account for additional savings as well.

Contact Customer Support

If you are still not sure which Jobber drill bit is right for you or you need help, then for further information please contact our team, and we will be happy to help you understand which ones are perfect for you and your team.

Standard Delivery Information

We have also extended our delivery service and ordering hours to offer you free next working day delivery, making your shipping experience even easier.

Place your order online by 7 p.m. and choose the delivery charge that suits you best to ensure the timely, UK mainland hassle-free delivery of your products.

Standard free next-day delivery is also available for all products ordered within the specified time, with free shipping and a good returns policy for certain items as well.

Who Is MSC Direct?

Here at MSC Industrial Supply Co., we are a leading supplier of industrial tools, equipment, and maintenance supplies across the United Kingdom and can also offer you trade accounts, along with a wide range of inserts in our product range above.

As a result, we can offer you a vast selection of similar products, including Blacksmith drill bits, countersinks, masonry drill bits, hand tools, indexable insert drills, cutting tools, abrasives, power tools, Reamer tools, and safety equipment, many of which are available with special offers.

We also serve a wide range of industries, from manufacturing and engineering to maintenance and beyond.

Consequently, our outstanding customer service and expert technical team, fast delivery times, and technical support make us a trusted partner for all your business needs as a result.