FAQs
Why is the lock ring on my Alarm Lock PG21 Series Pilfergard Door Alarm not threading correctly into the cylinder I have provided?
The lock ring that secures our cylinder to the PG21 utilizes National Fine (UNF) threading as opposed to National Coarse (UNC) threading. The finer UNF threading allows for better load-carrying ability. Finer pitch threads are used mostly in applications where safety or where loosening due to vibration or shock would be an issue.
