Security Rated Steel Door - SR4

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The Securidor+ S4 security door range is accredited to offer a high level of security against potential attacks from heavy duty tools such as felling axes and disc grinders. These single and double door sets are available in a wide range of bespoke sizes, with over 100 locking options and a choice of RAL/ BS colours. The range is suited for use in high-security installations, such as the Ministry of Defence, banks, schools, utility buildings, sub-stations and Home Office approved gun rooms. Bespoke security-rated steel door-sets. LPS1175: D10 Issue 8 Cert/LPCB ref. 1542c .

  • Secure for sure with Strongdor
  • 129 locking systems available
  • Compatible with access controls
Unique Range Features

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Easy fit doors
1 year warranty

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Made in Britain Colour

Product Features

Height Icon

Single - up to 2.75m
Double - up to 2.75m

Width Icon

Single - up to 1.284m
Double - up to 2.492m

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Acoustic Rating

Est 35 dB

Further information


The welded frame is made from reinforced 1.5mm galvanised steel and a 38mm x 100mm single rebated profile. It is reinforced at hinges, lock keeps and fixing points.

Manufactured from 1.5mm galvanised attack face steel with 1.5mm inner face, the composite door leaf is 51mm thick with astragal lip to the closing edge. It weighs approximately 80kg per square meter.

Key Features
The range is certified to LPS1175 SR4, and fitted with extreme heavy duty hinges complete with 2 integral dog bolts per hinge. Constructed to resist attack from high powered cordless tools, felling axes, disk grinders, jigsaws etc.

Certified by the Loss Prevention Certification Board to LPS 1175 SR1 Issue 7 Cert/LPCB Ref. 1542a .

Leading face fits under the door.

Choice of personnel, panic and escape hardware, with over 100 locking options available - including single and multi-point bolting. All escape hardware complies with BS EN 179. A full list of compliant hardware can be found at .

Wide choice of finishes available including powder coated finish from our range of RAL or BS colours.

Optional Extras
Certified Louvres available up to 400mm square.

Suitable Substrate
Reinforced brickwork/blockwork, reinforced concrete or structural steelwork.
Minimum Fixing Size - M12

Standard Threshold

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Securidor Typical Leaf and Frame

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Securidor+ Level 4

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Standard Colours & Coatings

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SR4 Steel door fitting instructions

SR4 Fitting and Maintenance Instructions

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Door Configurations

Door Configurations for Steel Doors with security rating 3 & 4

Sr3 Doubles
Sr3 Singles

Over 150 colours available

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Frequently Asked Questions

Which security door is the best?

Unfortunately there is no simple answer to this question as all security rated door-sets have protection enhancement. The level of security required for your door-set will be dependent on the location and specification of your installation.

Check out our documents LPS 1175 vs PAS 24:2016 and LPS 1175 Explained to see which security rating may be best for you!

Who is responsible for ensuring the sales quotation meets the specification and building regulations, including location and method of installation?

It is the customer’s responsibility to ensure all details within the sales quotation / sales order meet the exact specification and / or original enquiry and are compliant with current building regulations including location and method of installation.

We are here to help and advise only and cannot accept responsibility for discrepancies after the order is confirmed.

Strongdor Terms and Conditions

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