Jonas Olesen November 1, 2024 6 min read

Home Office Body Armor Standard 2017 (knife and spike)

 

The Body Armor Standard 2017 for stab-proof vests differs from the earlier HOSDB 2007 standard. The UK Home Office has opted to include only two stab-proof levels in this updated standard, based on findings from a 2000 study by Horsfall.

The study found that 90% of stab attacks with a force up to 33 joules would be effectively stopped by a stab-proof vest, as most individuals cannot exert much greater force. Consequently, KR3 and SP3 protection levels were eliminated in the updated standard.

Photograph showing typical stab test configuration

Test equipment used for Body Armor Standard 2017 can be seen in the image above.

The test uses a drop method, where the knife blade or spike is mounted on a 1,900-gram sabot (or “knife holder”) and dropped from a specified height to simulate different protection levels. Inside the sabot are two layers of hard foam, allowing the knife to retract slightly upon impact, mimicking the effect of a real-life stabbing action.

All testing equipment is designed to realistically simulate human reactions, whether delivering or receiving a stab. For this reason, the backing material under the stab-proof vests comprises multiple layers of foam and rubber, closely replicating the density and responsiveness of the human body.

For flat stab-proof vests, a flat test backing is used. In contrast, molded stab-proof vests are tested with a torso-shaped backing material that simulates the human form. Body armor with specific contours, such as female vests shaped for the chest, must be tested on a molded torso to ensure accurate performance results.

Test knife and test spike in the Home Office Body Armor Standard

Both a knife (KR) and a spike (SP) are used in the Home Office Body Armor Standard 2017. These are both engineered blades, which mean they can be hammered into a wooden block several times without breaking apart. The test knife is specially designed for piercing and is sharper and more precise than typical kitchen or hunting knives one might encounter on the street.

The spike is more appealing to prison staff, which is more likely to get attacked by a homemade icepick. Please note that Body Armor Standard 2017 is made with the focus on the UK police and their duties, which is why the spikes must represent homemade spikes.

Stab and spike proof levels for Body Armor Standard 2017 just like the old HOSDB stab proof standard from 2007, you use both an E1 and E2 pressure. The E1 press will simulate the “normal” stab where the knife maximum can penetrate by 8 mm. This means that the knife cannot reach your internal organs and will only cause a superficial injury. The E2 pressure is increased by 50%, and the penetration from the blade cannot exceed more than 20 mm.

The reason for doing an E2 test is that a stab proof vest shouldn’t fail, at a greater pressure. This could have catastrophic consequences if the knife flies through the E2 pressure and has a greater penetration than the allowed 20 mm. That is why both E1 and E2 pressures are required for the stab test.

HOSDB 2017 stab-spike

  • The spike is NOT allowed to penetrate at all
  • SPL means “Single penetration limit”. When doing a full stab test only ONE stab is allowed to penetrate by 9 mm for E1 and 30mm for E2.