Schlage Locks: Setting the Industry Standard

Residential and Commercial Security

How Are Commercial Locks Graded?

Before a BHMA (Builders Home Manufacturers Association) approved commercial lock product hits store shelves, it has gone through a systematic testing process.  Lock products which pass the test and receive BHMA certification can be relied upon by consumers for both quality and safety.

During the testing process, which is conducted by independent laboratories according to BHMA specifications, locks are given a final “grade.”  Commercial locks are sold as Grade 1, Grade 2 and Grade 3.  Each grade denotes particular qualities about that lock model.  The grading system is useful for builders and contractors when it comes to choosing the right kind of lock for a specific application.

The Builders Home Manufacturers Association tests commercial locks on six points: operational, strength, cycle, security, material evaluations and finish.  The grade is assigned depending upon where a particular lock “scores” on these points.

The operational and finish points of the testing process hold identical standards for all three grades of locks.  For example, in the operational test, all three grades of locks require the same amount of force to turn the key or the lock lever (28 lbf-in 3Nm). 

The differences between the three grades lie within the strength, cycle and material evaluation portion of the test.  A grade 1 lock, the strongest grade available on the market, has a knob torque minimum of 300 pounds of force per square inch.  A grade 1 lock must be made of strong materials in order to withstand this type of force, and will typically last longer than a grade 2 or 3 lock.

This table shows a portion of the description of the test values used to determine lock grade. [1]

Test Type     Test Description           Grade 1                            Grade 2                            Grade 3

Strength            Torque min./knobs           300 lbf-in (34 Nm)       150 lbf-in (17 Nm)        120 lbf-in (14 Nm)

                              Torque min./levers          700 lbf-in (74 Nm)       450 lbf-in (50 Nm)        225 lbf-in (25 Nm)

Cycle                                                                     800,000                           400,00                               200,00

Material           Unlocked outside               250 lbf-in (28 Nm)        150 lbf-in (17 Nm)        120 lbf-in (14 Nm)

                             knob torque

                            Unlocked outside               450 lbf-in (50 Nm)        225 lbf-in (25 Nm)         180 lbf-in (20 Nm)

                            lever torque

To determine the grade of a commercial lock, look for the ANSI/BHMA certification information on the package and/or product information sheet.  The grade of any particular lock is also indicated by the last number of the product code.

Grade 1 locks, the strongest and most durable, are typically recommended for use in high traffic areas of commercial buildings.  Grade 1 locks are often referred to as “heavy duty” locks.   They are also recommended for use on exterior doors, since they offer the highest amount of security. 

Grade 2 locks are also known as “medium duty.”  They are recommended for use on interior doors where security is a priority.  Doors to offices or rooms which hold expensive office equipment or the company safe should have at least medium grade locks installed on all doors.

Grade 3 locks, also known as “standard duty,” are made for lighter applications.  Storerooms, janitors and supplies closets, staff lounges, or any room that is not meant for public access but doesn’t house expensive equipment can be outfitted with standard duty locks.

[1] “BHMA Standards at a Glance.”  ANSI/BHMA Standard A156.2-2003.  Builders Home Manufacturers Association.  2003.  (PDF file available at .)









February 18, 2009 - Posted by | Commercial and Residential Security

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