---
kind: "section"
citation: "16 C.F.R. § 1203.16"
title: "16"
number: "1203.16"
heading: "Dynamic strength of retention system test."
url: "https://uscodex.org/cfr/16/1203.16"
---

# §1203.16. Dynamic strength of retention system test.

- (a) **Test equipment.**
  - (1) ISO headforms without the lower chin portion shall be used.
  - (2) The retention system strength test equipment shall consist of a dynamic impact apparatus that allows a 4-kg (8.8-lb) drop weight to slide in a guided free fall to impact a rigid stop anvil (see Figure 8 of this part). Two cylindrical rollers that spin freely, with a diameter of 12.5±0.5 mm (0.49 in.±0.02 in.) and a center-to-center distance of 76.0±1 mm (3.0±0.04 in.), shall make up a stirrup that represents the bone structure of the lower jaw. The entire dynamic test apparatus hangs freely on the retention system. The entire mass of the support assembly, including the 4-kg (8.8-lb) drop weight, shall be 11 kg±0.5 kg (24.2 lb±1.1 lb).
- (b) **Test procedure.**
  - (1) **Place the helmet on the appropriate size headform on the test device according to the HPI.** Fasten the strap of the retention system under the stirrup.
  - (2) Mark the pre-test position of the retention system, with the entire dynamic test apparatus hanging freely on the retention system.
  - (3) Raise the 4-kg (8.8-lb) drop weight to a height of 0.6 m (2 ft) from the stop anvil and release it, so that it impacts the stop anvil.
  - (4) **Record the maximum elongation of the retention system during the impact.** A marker system or a displacement transducer, as shown in Figure 8 of this part, are two methods of measuring the elongation.

## Notes

### Authority

Authority: 15 U.S.C. 2056, 2058, and 6001-6006. Subpart B is also issued under 15 U.S.C. 2063. Subpart C is also issued under 15 U.S.C. 2065.

### Source

Source: 63 FR 11729, Mar. 10, 1998, unless otherwise noted.