Home Office Body Armor Standard 2017 (knife and spike)
Body Armor Standard 2017 for stab proof vests is a bit different from the previous HOSDB 2007 standard. From Home Office, one has chosen to have only 2 stab proof levels, which is determined on the basis of a survey made by Horsfall in 2000.
The survey showed that 90% of all stabs with a force of maximum 33 joules would be stopped in stab proof vest, where you as a human wouldn’t be able to stab much harder than this, which is why KR3 and SP3 have been eliminated.
Test equipment used for Body Armor Standard 2017 can be seen on the image above.
The test consists of a drop test where the knife blade or the spike is placed on a sabot, weighing 1,900 grams. This is dropped from an height to simulate the individual protection levels. Inside the "sabot" (let's call the "knife holder") there are 2 layers of hard foam, which means that when the knife holder hits the stab proof vest, the knife will be pushed slightly up into the knife holder, just like if a man stabbed with a knife.
All equipment is designed to simulate how a person would react, whether you are stabbing or being stabbed. This is also why the background material, which lies under the stab proof vests, consists of several layers of foam and rubber, to represent a human body as best as possible.
For flat stab proof vests, a flat test background is used, and for molded stab proof vests there will be used a molded backing material with the shape of a human torso(Body armor that has a particular shape, such as female vests that are shaped by the chest needs to be tested on a molded torso)
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 knife is designed to pierce things, and is sharper and tighter than the normal kitchen knives, hunting knives and the like that you can meet 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 with 50%, and the penetration from the blade cannot exceed more than 20 mm.
The reason for doing an E2 test is that 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.
- 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.