Choosing between a pin locking fitting and a spring loaded fitting is one of the most common decisions when assembling an aluminium window or door. Both do the same job, joining two profiles at an angle with precision, but in different ways.
How a locking fitting works
A locking fitting is made of flat-winged profiles nested inside each other, with pins that lock the fitting into the profile chamber. Assembly is completed with a punch press and its die, giving a strong, repeatable joint. It is the classic workshop solution: robust, precise and available for every chamber, profile width and pitch on the market.
Estoal manufactures locking series in several pin diameters, from the T4 series, with Ø4 pins designed for narrow chambers, to larger-section series.
How a spring loaded pivot fitting works
In a spring loaded fitting the pin is movable: a spring holds it in place and lets it retract as the fitting slides into the profile, then snap into its seat. Assembly is faster and suits short runs or on-site work. Our TM spring loaded fitting is an Estoal patented design, and the TM45 is its most compact version for minimal chambers.
Which one to choose?
- Workshop production with a press: locking fittings give the best repeatability on long runs.
- Fast assembly with minimal tooling: spring loaded fittings simplify the job.
- Very narrow chambers: small-pin series such as T4, or the TM45 minimum spring fitting.
- In every case: the fitting must match the profile chamber and pitch. Check the dimensions in the table on each product page.
We help you choose
Unsure between two references? Send us your profile section and we will recommend the right fitting. Contact our technical department or browse all our aluminium corner fittings.
