StacksVerified U.S. regulatory reference

49 CFR §587.14

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The dimensions of the deformable face are illustrated in Figure 1 of this subpart. The dimensions and materials of the individual components are listed separately below. All dimensions allow a tolerance of ±2.5 mm (0.1 in) unless otherwise specified.
  1. (a)Main honeycomb block.
    1. (1)Dimensions. The main honeycomb block has a height of 650 mm (25.6 in) (in the direction of honeycomb ribbon axis), a width of 1,000 mm (39.4 in), and a depth of 450 mm (17.7 in)(in the direction of honeycomb cell axis).
    2. (2)Material. The main honeycomb block is constructed of the following material. The honeycomb is manufactured out of aluminum 3003, with a foil thickness of 0.076 mm (0.003 in) ±0.004 mm (0.002 in) a cell size of 19.14 mm (0.75 in), a density of 28.6 kg/m 3 (1.78 lb/ft 3) ±2kg/m 3 (0.25 1b/ft 3), and a crush strength of 0.342 MPa (49.6 psi) + 0%−10%, measured in accordance with the certification procedure described in § 587.15.
  2. (b)Bumper element honeycomb.
    1. (1)Dimensions. The bumper element honeycomb has a height of 330 mm (13 in)(in the direction of honeycomb ribbon axis), a width of 1,000 mm (39.4 in), and a depth of 90 mm (3.5 in) (in the direction of honeycomb cell axis).
    2. (2)Material. The bumper element honeycomb is constructed of the following material. The honeycomb is manufactured out of aluminum 3003, with a foil thickness of 0.076 mm (0.003 in) ±0.004 mm (0.0002 in), a cell size of 6.4 mm (0.25 in) ±1 mm (0.040 in), a density of 82.6 kg/m 3 (5.15 lb/ft 3) ±3 kg/m 3 (0.19 lb/ft 3), and a crush strength of 1.711 MPa (248 psi) + 0% −10%, measured in accordance with the certification procedure described in § 587.14.
  3. (c)Backing sheet.
    1. (1)Dimensions. The backing sheet has a height of 800 mm (31.5 in), a width of 1,000 mm (39.4 in), and a thickness of 2.0 mm (0.08 in) ±0.1 mm (0.004 in).
    2. (2)Material. The backing sheet is manufactured out of aluminum 5251/5052.
  4. (d)Cladding sheet.
    1. (1)Dimensions. The cladding sheet of the main honeycomb block has a total length of 1,700 mm (66.9 in), a width of 1,000 mm (39.4 in), and a thickness of 0.81 mm (0.03 in) ±0.07 mm (0.003 in). It is shaped as indicated in Figure 1.
    2. (2)Material. The cladding sheet of the main honeycomb block is manufactured out of aluminum 5251/5052.
  5. (e)Bumper element honeycomb facing sheet.
    1. (1)Dimensions. The bumper facing sheet has a height of 330 mm (13 in), a width of 1,000 mm (39.4 in), and a thickness of 0.81 mm (0.03 in) ±0.07 mm (0.003 in).
    2. (2)Material. The bumper element honeycomb facing sheet is manufactured out of aluminum 5251/5052.
  6. (f)Adhesive. The adhesive used throughout is a two-part polyurethane. (such as Ciba-Geigy XB5090/1 resin with XB5304 hardener, or equivalent).