Unite thread forming type B
Thread Forming Type B Screws for Heavy Section Steel
Thread forming type B screws for pre-drilled heavy steel connections
Our thread forming type B screws are designed for pre-drilled fastening into heavy section steel. This family is intended for steel thicknesses from 4 to 25 mm, making it relevant when lighter thread-forming families are no longer the right fit and you need a fastening solution for heavier steel sections.
When choosing within this range, the key questions are usually substrate thickness, drill-hole diameter, corrosion requirement and clamp length. We help contractors, steelwork teams and sheet metal professionals choose the right B-thread screw so the connection fits the steel, the build-up and the project environment.
How our B-thread range is typically chosen
Shorter B-thread screws for compact steel build-ups
Choose our shorter B-thread screws when the connection is relatively compact and you want a clean pre-drilled fixing into heavy section steel without unnecessary extra length. This is the better fit when the outer build-up is tight but the steel still sits inside the 4–25 mm thickness range for this family.
See sizes and technical details for our shorter B-thread screws on page 36 in the catalogue
Longer B-thread screws for thicker build-ups and more reach
Use our longer B-thread screws when the connection needs more reach and more clamp length into heavy section steel. They are the stronger choice when short screws would leave too little working length for the build-up, but you still want the same B-thread installation logic and pre-drilled steel connection.
See longer sizes and range details for our B-thread screws on page 36 in the catalogue
Stainless B-thread screws for higher corrosion demands
Choose our stainless B-thread screws when the project environment demands a more corrosion-resistant solution. This part of the range lets you keep the same B-thread fastening concept for heavy section steel while stepping up material choice for more exposed conditions or more demanding specifications.
See stainless B-thread sizes and details on page 36 in the catalogue
Detailed thread forming type B data in our catalogue
Below, you can open the catalogue page for our thread forming type B screws. This is where you can compare the family in more detail, including available lengths, material choice and the installation notes that matter when fastening into heavy section steel.
The catalogue page is especially useful when you need to confirm whether a shorter or longer screw is more appropriate, whether carbon steel or stainless steel is the better fit, and which guideline drill-hole diameter should be used for the steel thickness in the connection.
Need help choosing the right B-thread screw?
If you are comparing steel thickness, hole diameter, corrosion requirement or clamp length, our team can help you narrow the choice quickly. We support contractors, steelwork teams and technical buyers who need the right thread forming screw for the connection rather than a generic answer.
How do I know thread forming type B is the right family for our connection?
Choose thread forming type B when you are fastening into pre-drilled heavy section steel rather than timber or lighter-gauge profiles. This family is intended for steel thicknesses from 4 to 25 mm, so it becomes relevant when lighter thread-forming families no longer match the substrate you are fixing into.
What steel thickness is thread forming type B intended for?
Thread forming type B is intended for heavy section steel with thickness 4–25 mm. That range is one of the main reasons to choose this family, because it helps separate B-thread screws from lighter thread-forming or self-drilling options that belong on other pages.
Why does the drill-hole diameter matter so much with B-thread screws?
It matters because this family is designed for pre-drilled holes, so the hole size affects how the screw forms its thread in the steel. The catalogue gives guideline values of 5.5 mm for steel thicknesses 4.0–6.0 mm and 5.7 mm for 7.0–25.0 mm, which helps reduce the risk of choosing a connection setup that does not behave as intended.
How do I choose between carbon steel and stainless steel B-thread screws?
Start with the environment and corrosion requirement. Carbon steel can be the practical choice for less demanding conditions, while stainless steel is the better option when the specification or exposure level calls for a more corrosion-resistant solution. The right answer depends on where the connection will live, not only on the steel thickness.
Can Unite help us choose the right length and clamp length for our project?
Yes. The right length depends on the full build-up of the connection, not just the steel you are fastening into. We can help you review the outer build-up, the steel thickness and the project environment so you can choose a B-thread screw that gives the connection the reach and fit it actually needs.