We design and build Master Key systems ranging from 3 to several hundred locks depending on our customers’ requirements.

We design and build Master Keyed systems to suit your individual requirements in our Coventry work shop, using Grundmann 6 pin restricted section keys and cylinders.

With our system there are very few locks which cannot be Master Keyed. We have a wide range of padlocks which can be integrated into your suit so we should be able to Master Key all of your doors including Panic bars, external lock cylinders and gates.

Many businesses can benefit from a master key system including hotels, shops, offices, general landlords, schools and factories.

Your Master Key System from start to finish:
You tell us what type of building you would like to master key.
Several Rental Properties or A School or Your house, your office, garages and out building, and holiday home. Whatever your requirements we can meet them.
• You tell us how many doors and where your doors are or we visit property (in Coventry) and check
• You tell us who need access i.e. family, staff, tenants.
• You tell us who can go where.
• You tell us how you want your keys stamping i.e. off for office, F1 for Flat1, 79H for 79 Hill St or even Mum
• We design a plan which will give every one access to where ever they have to go only, and they will only need one key.
• We check the plan with you and build your locks.

All our locks and keys are stamped as agreed.


Our pExtra+ system of 3 profiles with an over riding common key is unique to RJ Parker Coventry.
pExtra+ has EN1303 key related security Grade 6 and is up to kite marked approved standard and is TS007 1-star (to date only cylinders built in Kaba factory can carry the actual kite mark and stars) they are anti drill, anti pick and anti bump, (the anti bump is optional in Master key systems because it can limit the size of suit and is not normally needed).

The pExtra+ features a sophisticated patented key profile with a “branch groove”, duplicate keys cannot be made using current commercial key milling machines. There is a blocking pin which verifies the presence of the branch groove, if the branch groove is not detected the blocking pin prevents the key from turning completely in cylinder meaning an illegally copied key (using a commercial milling machine) will not work.