Our metric screws span machine screws, self-tapping screws, set screws, wood screws, and countersunk head screws in a full range of drives and head styles. From precision instrument fasteners to structural fixings, we stock the DIN and ISO screws engineers rely on across electronics, machinery, joinery, and general assembly.

Screws - Metric Sizes

What Is a Screw?

A screw is a threaded fastener designed to be driven into a mating thread, a tapped hole, or directly into a material such as wood, plastic, or sheet metal, forming a secure mechanical joint. Unlike a bolt, which is typically paired with a nut, many screws create their own thread or engage a pre-tapped hole. The huge variety of head styles, drive recesses, and thread forms means there is a screw optimised for nearly every fastening task.

At Metric Specialties we carry the complete metric screw family: machine screws (DIN 84, DIN 963, ISO 7045) for tapped holes and nuts; self-tapping and self-drilling screws for sheet metal and plastic; grub and set screws (DIN 913–916) for locating and clamping; and countersunk, pan, cheese, and button head styles in slotted, Phillips, Pozidriv, Torx, and hex socket drives. Whether the job calls for an M1.6 instrument screw or an M20 structural fixing, the right head, drive, and material combination is in stock.

Key Features and Benefits

• Wide Head and Drive Selection: Countersunk, pan, button, cheese, and hex heads in slotted, Phillips, Pozidriv, Torx, and socket drives suit any tool and finish.
• Self-Forming Threads: Self-tapping and self-drilling screws cut their own thread, removing the need for pre-tapping in sheet metal and plastic.
• Precise Clamping: Machine screws thread into nuts or tapped holes for accurate, repeatable clamping in machinery and electronics.
• Clean Finishes: Countersunk heads sit flush for a smooth, snag-free surface in joinery and panels.
• Corrosion Options: Zinc-plated and stainless grades protect against rust in demanding environments.

Materials and Finishes

• Carbon Steel (Zinc Plated): Cost-effective corrosion protection for general assembly and joinery.
• Case-Hardened Steel: Tough surface for self-tapping and self-drilling screws that must cut their own thread.
• Stainless Steel A2 / A4: Rust-resistant grades for outdoor, marine, and hygienic applications.

Standards Compliance

• ISO 7045 / DIN 7985  Pan head machine screws.
• ISO 7046 / DIN 965  Countersunk head machine screws.
• DIN 7981 / ISO 1479  Self-tapping screws.
• DIN 913–916  Set (grub) screws.

Common Applications and Industries

Machine screws are found throughout electronics, instrumentation, and enclosure assembly, threading into tapped holes or nuts to hold panels, brackets, and components precisely. Self-tapping and self-drilling screws dominate sheet-metal fabrication, HVAC ductwork, and automotive trim, cutting their own thread to speed high-volume production. Wood screws and countersunk screws serve joinery, cabinetry, and construction, where a flush, strong fixing into timber is required.

Set (grub) screws appear in power transmission, locking pulleys, gears, and collars onto shafts. Across appliances, furniture, machinery, and general manufacturing, the sheer variety of head styles, drives, and materials means a screw can be optimised for appearance, torque, corrosion resistance, or assembly speed. Choosing the right combination keeps assembly efficient and joints reliable.

How to Choose the Right Screw

First identify what the screw threads into: a tapped hole or nut calls for a machine screw, sheet metal or plastic suits a self-tapping screw, and timber calls for a wood or coach screw. Then pick the head style for the finish you need: countersunk for flush, pan or button for a low rounded profile, cheese for slotted work, and hex socket for high torque.

Select the drive to match your tooling: Torx and Pozidriv resist cam-out and suit powered assembly, while slotted and Phillips serve lighter or traditional work. Finally choose the material and finish  zinc-plated steel for general use, case-hardened for self-tapping, and A2 or A4 stainless for corrosion resistance  and confirm the length gives adequate thread engagement without protruding excessively.

Size Range and Availability

Available from M1.6 through M20 across machine, self-tapping, set, and wood screw families, in zinc-plated steel and A2/A4 stainless.

Why Buy From Metric Specialties

As dedicated metric fastener specialists, we hold screws in the sizes, grades, and finishes that engineers actually need, backed by clear DIN and ISO standard references so you can specify with confidence. Every item is sourced to recognised standards and quality-controlled, giving you consistent thread fit, strength, and corrosion performance across repeat orders.

Whether you need a single item for a repair or bulk quantities for production, our range, technical guidance, and fast dispatch help you find the exact fastener for the job. If you are unsure which size, grade, or finish suits your application, our team can help you match the right product to your load, environment, and standard, so your assemblies are reliable and built to last.

Frequently Asked Questions (FAQs)

1. What is the difference between a screw and a bolt?

A screw is generally driven into a tapped hole or material to form its own engagement, while a bolt passes through a clearance hole and is tightened with a nut. Screws often create or engage their own thread; bolts rely on a mating nut.

2. What types of screws do you stock?

We stock machine screws, self-tapping and self-drilling screws, set (grub) screws, wood screws, and countersunk, pan, button, cheese, and hex head styles in a full range of drives and materials.

3. What is a machine screw used for?

Machine screws are used to fasten into a tapped hole or a nut in metal or plastic assemblies  common in electronics, instruments, machinery, and enclosures where a precise, reusable threaded joint is needed.

4. What is the difference between Pozidriv and Phillips screws?

Both are cross-drive recesses, but Pozidriv has additional radial ribs that reduce cam-out and allow higher torque. A Pozidriv bit fits a Pozidriv screw best; using a Phillips bit can slip and damage the recess.

5. What is a self-tapping screw?

A self-tapping screw cuts its own thread as it is driven into sheet metal, plastic, or a pilot hole, removing the need for a pre-tapped thread. Self-drilling variants also bore their own pilot hole.

6. What is a set screw or grub screw?

A set screw (grub screw) is a headless threaded screw driven fully into a tapped hole, commonly used to lock a component such as a pulley or collar onto a shaft through friction or a pointed tip.

7. Are your screws available in stainless steel?

Yes. We stock A2 and A4 stainless screws across most head and drive styles for corrosion-resistant use in marine, outdoor, food, and hygienic applications.

8. What drive types are available on your screws?

We supply slotted, Phillips, Pozidriv, Torx, and hex socket drives depending on the screw type, letting you match the recess to your tooling and torque requirements.

9. What size screws do you stock?

We stock M1.6 through M20 across the machine, self-tapping, set, and wood screw families, in zinc-plated steel and A2/A4 stainless.

10. How do I choose the right screw head style?

Choose countersunk for a flush finish, pan or button for a rounded low-profile head, cheese for a straight-sided head in slots, and hex socket for high-torque machine assembly.