I recently moved into a new flat with period wooden sash windows. Obviously they are not the most secure and any additional security we can add would be great. One of the sets of windows had 1 of these bolts in it but there are spaces for more, however I cannot seem to find any more of them to buy.
It is a 75mm long bolt with thread at one end with a square drive type (see attached picture). The threaded part is 25mm long, 7mm diameter and the thread size appears to be 1.42mm. The pin is 5mm diameter and 50mm long.
If anyone knows what the name for this particular type of bolt is I would be appreciative.