NIJ 0115 Body Armor Stab Resistance

The "NIJ 0115 Stab resistance of body armour" standard, developed by the National Institute of Justice (NIJ), is an equipment performance standard for determining the stab resistance of personal body armour and was developed in collaboration with the Police Scientific Development Branch and the Law Enforcement Standards Office at the National Institute of Standards and Technology in the United Kingdom. It was produced as part of the National Institute of Justice's law enforcement and criminal justice standards and testing programme.

This standard includes minimum performance requirements for typical pointed and edged weapon-resistant body armor and the test methods to be used for this evaluation. This standard is the first U.S. standard to address the threat posed by pointed and edged weapons. The improvements are intended to increase the realism and reproducibility of the test. This standard provides enhanced options to police purchasing units and users through the introduction of a range of protection levels. This standard is designed as a procurement aid and provides rigorous and detailed test methods.

Briefly, this standard was developed through cooperation between the United States and the United Kingdom. The purpose of this standard is to specify minimum performance requirements and test methods for cut resistance of personal body armor designed to protect the torso against cutting and stabbing threats. This standard is based on technical studies conducted by several organizations.

The scope of this standard is limited to cut resistance only. This standard does not address ballistic threats, as these are covered by the standard “NIJ 0101.04 Ballistic Resistance of Personal Body Armor”. This standard does not directly address cut threats, however, testing has shown that cut threats are much less easily defeated and that body armor that can defeat cut threats will perform satisfactorily against cut threats.

The NIJ 0115 standard specifies minimum performance requirements and test methods for stab-resistant body armor designed to protect against stab, i.e., blade, and pointed knife threats for U.S. criminal justice personnel. These test methods have been developed and validated for commonly available armor designs. Some armor designs may require additional or modified testing beyond that specified in this standard.

This standard only addresses stab-resistant panels designed for torso protection and does not address extremity protection. Body armor covered by this standard is classified into two levels of protection based on mission requirements and the threats expected to be encountered in specific operational environments:

• Commercial threat protection: Commercially produced knives and pointed weapons commonly encountered outside controlled access facilities or in the prison intake area.
• Improvised threat protection: Improvised or prisoner-made weapons typically encountered inside controlled-access facilities such as prisons, detention centers, and jails.

This standard does not address ballistic resistant body armor. This standard applies to certification testing or research and development testing.

The environmental conditions for the tests described in this standard are determined as follows:

• Temperature: 21 degrees plus/minus 6 degrees
• Relative humidity: 50 percent plus/minus 20 percent
• Conditions are recorded before and after a complete test series for an armor model and at each 4-hour time interval during the test session.

Drop tube tests are performed using the guide rail drop tube assembly shown in the standard appendix (Appendix B). This system is carefully designed to ensure that the drop mass falls under the influence of gravity and strikes the armour sample at a predetermined impact point. Guide rails located within the tube prevent the drop mass from rotating about its vertical axis during its descent and ensure that the test knife blade or spike strikes in the correct orientation and continues in that orientation until it comes to rest.

The pipe and drop mass are checked regularly to ensure that the drop mass can fall freely from the pipe without being hindered by damaged areas of the pipe's internal walls or by rough edges in the nylon body of the drop mass. The drop pipe apparatus should be capable of demonstrating repeatable drop velocities to within plus/minus 0,05 m/s of the nominal velocity.

The drop mass consists of four basic parts:

• A threatening weapon (i.e. one of the blades or spikes).
• A steel and aluminum alloy sub-mass that holds the threat weapon and has a mass of 650 g plus/minus 7 g with the threat weapon attached.
• A nylon upper mass which houses the lower mass and allows it to slide vertically within a cavity within the nylon body. The mass of the upper mass is 1250 g plus/minus 13 g and the overall dimensions are 97 mm in diameter and 400 mm in length.
• Two closed cell polyethylene foam discs, each 30 mm thick and 50 mm in diameter, are placed inside the nylon upper mass and sandwiched between the bottom of the lower mass and the nylon casing. They are compressed as the lower mass is pushed further into the upper mass body. The foam elements create the damping effect.

A suitable method must be used to accurately measure the velocity of the falling mass within the velocity measurement zone. The measuring equipment must measure the velocity with an accuracy of plus/minus 0,05 m/s or better.

The test knife blades and tang are designed to be representative of the broad spectrum of actual knives used in attacks on law enforcement and correctional officers. Each test knife blade or tang shall be inspected to ensure that the overall surface is clean and free of rough edges and that the knife blade or tang meets the requirements of the accompanying engineering drawings (Appendix A). Each test knife or tang shall be subjected to a sharpness test and a hardness value of -50 to -150 on the Rockwell C scale shall be required.

Our organization has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. Among the numerous tests, measurements, analyses and evaluation studies provided for businesses in various sectors, there are also testing services in accordance with the "NIJ 0115 Body armor stab resistance" standard.