Reinforced Frames

Window Screws Made for Reinforced Frames

Using the wrong screw can crack your frame. It can also pull straight out. Reinforced window frames have a steel insert inside. It sits inside the uPVC or aluminium profile. Standard gimlet point screws are made for plain uPVC only. They cannot get through steel. They may also split the frame around it.

You need a self-drilling screw for reinforced frames. The tip works like a small drill bit. It cuts through the steel as you drive the screw in. No pre-drilling needed. No cracked frames. This collection has all the right products. Browse our full range of screws for reinforced frames from TIMCO.

Products come in packs of 200, 500, and 1000. Thread types, point styles, and head shapes vary. Always check the product spec before you order.

Three Material Grades to Choose From

The material you pick matters. It affects rust resistance, hardness, and where you can use the screw. Three grades are in this collection. They are not the same. Do not swap one for another. Check your window spec first.

Head Types in This Collection

Five head types are available here. The head shape affects how the screw sits on the frame or fitting. Some hardware needs a set head type. Follow that guidance if it exists.

Sizes and Lengths in This Range

Five thread sizes are in stock: 3.9mm, 4.2mm, 4.3mm, 4.8mm, and M4 metric thread. Not all sizes come in every head type or finish. Use the filters to find the right match for your job.

How to Pick the Right Screw

Start with the fitting. Most hardware will list the screw size and head type it needs. Follow that first. Do not guess.

Next, pick the right material. For most UK window jobs in dry areas, carbon steel zinc is fine. For coastal or wet sites, use stainless steel. Grade 410 is the better choice for self-drilling into steel reinforcement. It is harder than A2-304 and keeps its tip shape better.

Then check the length. The screw must go through the outer uPVC and into the steel insert. Too short and it only grips uPVC. Too long and it pokes through the inside of the frame. A 25mm screw works for most standard frames. Use 38mm to 60mm for deep or double-wall frames.

Finally, check the point type. This range uses three main point types:

Screw Guide by Job Type

Use this table to match the right screw to your task.

Other Window Screw Collections

Working on reinforced frames with friction stays? Some products here will work. But for a full dedicated range, visit our reinforced frames friction stay screws collection. It has the correct shallow pan head types for stay arm clearance.

Working on plain uPVC frames with no steel insert? This range is not the right one. Go to our unreinforced frames window screws instead. For friction stays on plain frames, see the unreinforced frames friction stay collection.

Need something less common? Our specialist window screws range may have what you need. To see all frame types in one place, visit the full window fabrication screws section.

Frequently Asked Questions

Find the Right Screw for Your Job

Use the filters on this page to narrow down by thread size, head type, material, finish, and length. With 107 products across five thread sizes and three material grades, this range covers most reinforced uPVC and aluminium window frame jobs in the UK.

Before you order, check the size, length, head type, and material against your window spec. All products are TIMCO window fabrication screws. Packs of 200, 500, and 1000 are available. Order before 2 pm for next-day UK delivery.