Tested in accordance to Japanese Industrial Standards – JIS S 1037:1989 and achieved an integrity of 82 minutes over 1 hours @ 1000 Degree Celsius. APS Strike bolt are made from solid 2 diameter Polish Shaft finished with chrome. APS 7 Lever double bit Key Lock. Length and teeth design were designed to deter lock picking and has a safety locking/unlocking feature used in most banks. APS Best selling model for Commercial Series has a wall thickness of 86mm each side Secured by a thick fire and burglary barrier. Able to withstand up to 1000 Degree Celcius of continuous burning. APS Vertical rebate is situated right behind the door acting as a safety latch to prevent door opening from cutting of hinges. Be sure your door will stay where it is even without hinges.