Most stab vests are made from flexible materials like Kevlar and are classified as “soft body armour”, offering little or no protection against ballistic threats but have the benefit of being thinner and more flexible than ballistic level body armour which can be useful if you are often in physical altercations.
Various tests have been developed around the World to classify something as “stab proof”, however it is worth noting nothing is completely impenetrable and so a better term would be “stab resistant”. In the mid 1980’s the state of California Department of Corrections issued a requirement for a body armour using a commercial ice pick as the test penetrator. The test specified 109 joules (81ft-lbf) of energy and a 7.3kg (16lb) drop mass with a drop height of 153cm (60 inches) and an ice pick with a 4mm (0.16 inch) diameter with a sharp tip with a 5.4m/s (17ft/s) terminal velocity in the test.
Today the US has the National Institute of Justice (NIJ) set of standards which is based on the UK’s and offers tests for various threat levels – 1 = 24 joules, 2 = 33 joules and 3 = 43 joules. The PSDB standard in the UK was replaced with the current Home Office Scientific Development Branch (HOSDB) test specifications which introduced a more stringent testing procedure with more drops than the previous standard plus the introduction of the P1/B blade which is more aggressive than the P1/A blade.
Other tests can be conducted to check for spike and hypodermic needle protection as this is unfortunately a new threat. Some stab vests can protect against thick knife blades but a needle will penetrate easily. Some wearers therefore opt for hard body armour as it generally stops knife, spike and needle attacks as well as gun ammunition.
It is important to ensure whatever stab vest you choose that it is BRAND NEW and not re-conditioned or second hand and that there is INDEPENDENT certification showing it has been tested and passed the threat level you require.
A reputable test company who independently certifies body armour would conduct multiple attacks on the same stab vest to ensure it protects against a repetitive attack. An example would be 5 or more strikes on different areas and at different angles using an increased force. An example is below…
