Heavy duty patch fittings: size the door, not the label
Judge a patch fitting by the door it carries, not the label: 12 mm tempered glass weighs about 30 kg per square meter. Work out the leaf weight, then get the rated door weight for the fittings and floor spring in writing.
The set to order
| Part | What to check | Models |
|---|---|---|
| Bottom patch | Carries the leaf on the floor spring. Glass 8 to 12 mm. Door weight limit confirmed against your drawing. | F110 |
| Top corner patch | Pin type, top hinge corner. Glass 8 to 12 mm. Door weight limit confirmed against your drawing. | F111 |
| Floor spring | Ask for the rated door weight first. It is not listed. | F101 |
| Patch lock | Glass 8 to 12 mm. Add its weight to the leaf. | F123 |
| Pull handle | Glass 10 to 12 mm, 600 mm long. Add its weight to the leaf. | 100 |
What is published and what is not
Standard and heavy duty are trade labels with no shared definition. A label tells you nothing until a door weight stands beside it, so start from what is listed.
| Part | Published | Not published |
|---|---|---|
| F110 to F114 patch fittings | Glass 8 to 12 mm, stainless steel, iron chassis | Maximum door weight, width or height |
| F101 floor spring | Iron body, 304 stainless steel outer plates, footprint 308 × 108 mm, case depth 40.5 mm, adjustable latch and closing speed | Maximum door weight, maximum door width, opening angle, hold-open, single or double action |
| All of the above | Models, materials and dimensions as stated on each page | Load test results or cycle counts |
Step 1: work out the leaf weight
Allow 2.5 kg for every square meter of leaf and every millimeter of glass. That is a general glass figure, not a product rating. Multiply height by width by thickness by 2.5, then add the handle and lock. The table rounds to the nearest kilogram.
| Leaf size (mm) | Area | 8 mm glass | 10 mm glass | 12 mm glass |
|---|---|---|---|---|
| 900 × 2,100 | 1.89 m² | 38 kg | 47 kg | 57 kg (126 lb) |
| 1,000 × 2,400 | 2.40 m² | 48 kg | 60 kg | 72 kg (159 lb) |
| 1,100 × 2,700 | 2.97 m² | 59 kg | 74 kg | 89 kg (196 lb) |
| 1,200 × 3,000 | 3.60 m² | 72 kg | 90 kg | 108 kg (238 lb) |
Step 2: check every part takes your glass
Glass thickness is the one limit we do list. A set is only as wide as its narrowest part.
| Models | Listed glass |
|---|---|
| F110, F111, F112, F113, F114 | 8 to 12 mm |
| F123 patch lock | 8 to 12 mm |
| GL125 SS double door lock | 8 to 10 mm |
| Pull handles 100, 102, 104, 105, 106, 107 | 10 to 12 mm |
| F132 glass door handle | 8 to 12 mm |
Step 3: check the floor spring first
On a frameless door the floor spring carries the leaf and controls its closing, so in general its rating sets the limit for the whole door. The catalogue has one floor spring, F101, and we list no door weight for it. Ask for that figure before you size the glass.
Patch systems that do publish limits commonly state around 80 to 100 kg door weight and about 1,000 to 1,100 mm door width. Those numbers belong to those systems. They are a reason to ask the question, not a Stahlock rating.
When to ask for written confirmation
- The leaf weighs more than the supplier has confirmed in writing.
- The leaf is wider than 1,000 mm (39 in).
- The leaf is taller than 2,400 mm (94 in).
- The door faces the street and takes wind.
- The door sees constant traffic, such as a shop or station entrance.
What to ask any supplier
- What is the maximum door weight for this patch fitting?
- What is the maximum door width and height at that weight?
- What is the maximum door weight for this floor spring?
- Is that floor spring single action or double action?
- Does the floor spring spindle fit the socket in this bottom patch?
- Which liner or packer goes with my glass thickness?
- Which test report supports these figures?
Questions buyers ask
What is the difference between standard and heavy duty glass patch fittings?
There is no shared definition. The useful difference is the door weight a supplier will state for the part. If a heavy duty fitting comes with no maximum door weight, the label gives you nothing to check.
How much does a 12 mm glass door weigh?
About 30 kg per square meter. A 1,000 × 2,400 mm leaf is 2.4 m², so about 72 kg (159 lb) before the handle and lock.
Can F110 carry a 100 kg door?
That is not published, so nobody should promise it from the catalogue. Send your door size and glass thickness, and have the limit for F110 and F101 confirmed against your drawing before you order glass.
Does thicker glass mean I need heavier fittings?
Thicker glass adds weight: a 12 mm leaf weighs 50 percent more than the same leaf in 8 mm. F110 to F114 are recorded for the whole 8 to 12 mm range, so the check is on door weight, not on thickness alone.
Do you publish a load rating or test report for these fittings?
No load rating or test report is published for them. This guide says so plainly so that you can ask for what your project requires before you order.