A2 stainless steel safety frame cramps for fixing timber windows and door frames into masonry. Also suitable for restraining masonry to new and existing structures. Two 6mm holes and one 9mm hole. Available in 100mm, 150mm and 200mm sizes.
Size
Price
QTY
100
£128.50£154.20
150
£139.25£167.10
200
£149.75£179.70
Stainless steel safety frame cramps are the go-to fixing when you’re securing timber window and door frames into blockwork or brickwork. These are the A2 stainless steel version, which matters more than it might seem — ordinary mild steel frame cramps corrode, and once moisture gets into the joint between frame and masonry, you’re looking at staining, weakening, and callbacks nobody wants. Each cramp has two 6mm holes and one 9mm hole, giving you fixing options whether you’re screwing, nailing or using a shot firer into steelwork.
The safety end design is a detail worth appreciating. It reduces the chance of the cramp working loose or causing injury during handling and installation, which on a busy frame-out day with cramps being passed around and dropped into buckets, is genuinely useful rather than just a technical specification.
Where Stainless Steel Safety Frame Cramps Are Used
These are primarily a joinery and groundworks fixing, used wherever a timber frame needs to be tied back to a masonry structure. Window and door frame installation makes up the bulk of use, but they also appear in structural masonry restraint applications — tying new blockwork to existing walls, for instance, in non-structural contexts. Green oak and other hardwoods with naturally high tannin or acid content are a particular case where stainless steel is the only sensible choice; standard zinc-plated cramps will corrode in contact with green oak within a relatively short time, which is not a great result when it’s buried in a wall.
Sizes and the A2 Grade
Available in 100mm, 150mm and 200mm lengths, these cover the typical frame reveal depths you encounter on standard domestic and light commercial work. A2 stainless steel sits in the standard corrosion-resistance bracket — well suited to most UK construction environments, coastal work, wet or exposed locations, and anywhere the base material itself is corrosive. If you’re in a genuinely aggressive marine or chemical environment, A4 grade would be the step up, but for the vast majority of frame installation work these stainless steel safety frame cramps are exactly what’s needed.
Supplied in boxes of 250, which is a sensible quantity for anyone running through a new-build plot or a window replacement contract. You won’t run short mid-job, and the per-unit cost at box quantity makes it straightforward to price into a bill of materials without wincing.
Pro Tip: When fixing into green oak or other acidic timbers, always use stainless steel cramps rather than galvanised — the tannins in green oak will corrode standard coatings surprisingly quickly, and you won't see the damage until the frame starts moving.
Safety frame cramps are used mainly in joinery installation, groundworks and general building work. They fix timber door and window frames back to masonry construction, keeping frames secure and in position while the surrounding blockwork or brickwork is built up around them. They are also used to restrain masonry to existing structures in non-structural applications, such as tying new blockwork returns to established walls. The shot-fire fixing capability makes them useful on steel-framed construction too, where speed of installation matters on a busy commercial site.
Best For
Timber window frame installation
Timber door frame installation
Masonry restraint to existing structures
Green oak and acidic timber applications
Shot fired fixing into steelwork
Compatible With
Blockwork and brickwork masonry
Green oak and hardwood frames
Steel framing (shot fired)
New-build and retrofit construction
Standard screws and nails via 6mm holes
Bolts via 9mm hole
Key Specifications
Material: A2 stainless steel
Available sizes: 100mm, 150mm, 200mm
Two 6mm fixing holes
One 9mm fixing hole
Safety end design
Box quantity: 250
Not suitable for: Not suitable for structural masonry restraint applications where engineer-specified fixings are required. For highly aggressive marine or chemical environments, A4 stainless steel fixings should be specified instead.
Cramps are built into the masonry joint as the wall is constructed around the frame, or fixed back to an existing structure using the 6mm or 9mm holes as appropriate. Position the cramp so it sits level in the mortar bed with the fixing end flush against the frame. Where shot firing into steelwork, use the 9mm hole with the appropriate fastener for the steel thickness.
Make sure the frame is plumb and braced before you start building in or fixing off. Once the cramp is embedded in mortar it is not going anywhere, so any adjustment to the frame needs to happen before that point. On green oak frames especially, check that no mild steel fixings are mixed in with the stainless cramps by mistake — it is an easy error on a busy site and one that causes problems later.
Check that the frame is plumb, square and adequately braced before fixing
Select the correct cramp length to suit the frame reveal depth and wall construction
Position the cramp flat in the mortar bed with the safety end against the timber frame
Fix through the 6mm holes using screws or nails into the timber frame
Use the 9mm hole where a bolt fixing or shot-fired fastener is required
Build masonry up around the cramp, ensuring it is fully bedded in mortar
Check frame alignment again before mortar sets and make any adjustments immediately
Why do I need stainless steel frame cramps rather than standard galvanised ones?
In most external or damp environments, galvanised cramps will eventually corrode, especially if they are in contact with acidic timbers like green oak. A2 stainless steel resists corrosion far better and is the correct choice for any exposed, coastal, wet or chemically active application. It also prevents the rust staining you sometimes see bleeding through render or mortar on older buildings where standard cramps were used.
Can these be used for restraining masonry as well as fixing frames?
Yes, safety frame cramps are commonly used to restrain masonry to new and existing structures in non-structural applications, such as tying a new blockwork return to an established cavity wall. They are not a substitute for engineer-specified structural ties, so if your project has a structural engineer's spec, check it before substituting.
Manufactured from A2 grade stainless steel, these frame cramps offer solid corrosion resistance for standard UK construction environments including exposed, coastal and damp locations. A2 stainless contains chromium and nickel, giving it good general-purpose resistance to oxidation and moderate chemical attack. Each cramp features a safety end profile and three fixing holes: two at 6mm diameter for screw or nail fixing, and one at 9mm for bolt or shot-fired fasteners. Suitable for embedding in mortar beds or direct fixing to masonry and steelwork.
Material
A2 Stainless Steel
Available Sizes
100mm, 150mm, 200mm
Fixing Holes
Two 6mm, one 9mm
End Type
Safety end
Box Quantity
250
Finish
Stainless (natural)
Size
100, 200, 150
Box Quantity
250
Reviews
There are no reviews yet.
Be the first to review “Safety Frame End Cramps – Stainless Steel – Box 250”Cancel Reply
Reviews
There are no reviews yet.