Armor Areal Densities

(Created 1 May 2010)
(Updated August 2016)

“Standard” Homogeneous Steel Armor

References:
US Battleships: An Illustrated Design History by Norman Friedman
Japanese Cruisers of the Pacific War
TenCate Ceramic Armor Systems Brochure (509 kb PDF)
CG-D-05-89: Evaluation of Composite Armor for Coast Guard Vessels, June 1988 (2.6 MB PDF)

ARL-RP-8 October 2000 – Performance Metrics for Composite Integral Armor (2.5 MB PDF) specifically THIS image.

My own Calculations on Weight.

Areal Density
(psf = Pounds Per Square Foot)

Thickness of Plate

Armor Protection Notes

10 psf
(actually 10.21 psf)
(49.85 kg/m3)

0.25” (6.35mm)


15 psf
(actually 15.31 psf)
(74.75 kg/m3)

0.375” (9.52mm)

Multi-Hit for
5.56mm M193 Ball
(STANAG 4569 Threat Level 1)
and
155mm Artillery Fragments at 100m

20 psf
(actually 20.42 psf)
(99.7 kg/m3)

0.5” (12.7mm)

Multi-Hit for
7.62x39 BZ AP
(STANAG 4569 Threat Level 2)
and
155mm Artillery Fragments at 80m

25 psf
(actually 25.52 psf)
(124.6 kg/m3)

0.625” (15.88mm)


30 psf
(actually 30.62 psf)
(149.5 kg/m3)

0.75” (19.05mm)

Multi-Hit for
7.62x63 M2 AP
(STANAG 4569 Threat Level 3)
and
155mm Artillery Fragments at 60m

35 psf
(actually 35.73 psf)
(174.45 kg/m3)

0.875” (22.23mm)


40 psf
(actually 40.83 psf)
(199.35 kg/m3)

1” (25.40mm)


50 psf
(actually 51.04 psf)
(249.2 kg/m3)

1.25” (31.75mm)


60 psf
(actually 61.25 psf)
(299.05 kg/m3)

1.5” (38.1mm)

Multi-Hit for
12.7x99 M2 AP
(US Army FCS
Protection Level Baseline)

70 psf
(actually 71.46 psf)
(348.9 kg/m3)

1.75” (44.45mm)

Multi-Hit for
14.5×114mm B32 AP
(STANAG 4569 Threat Level 4)

80 psf
(actually 81.76 psf)
(399.19 kg/m3)

2” (50.8mm)


90 psf
(Actually 91.87 psf)
(488.55 kg/m3)

2.25” (57.15mm)


100 psf
(actually 102.08 psf)
(498.4 kg/m3)

2.5” (63.5mm)


120 psf
(actually 122.5 psf)
(598.1 kg/m3)

3” (76.2mm)


140 psf
(actually 142.91 psf)
(697.75 kg/m3)

3.5” (88.9mm)

25×137mm APDS-T
(STANAG 4569 Threat Level 5)
(GENERAL GUESS)

163.33 psf
(797.45 kg/m3)

4.0” (101.6mm)


183.75 psf
(897.15 kg/m3)

4.5” (114.3mm)


204.16 psf
(996.8 kg/m3)

5.0” (127mm)


224.58 psf
(1096.5 kg/m3)

5.5” (139.7mm)


245 psf
(1196.2 kg/m3)

6.0” (152.4mm)

30×173mm APFSDS
(STANAG 4569 Threat Level 6)
(GENERAL GUESS)

and

NATO Single Medium Target

265.41 psf
(1295.85 kg/m3)

6.5” (165.1mm)


285.83 psf
(1395.54 kg/m3)

7.0” (177.8mm)

NATO Single Heavy Target

306.24 psf
(1495.2 kg/m3)

7.5” (190.5mm)


326.66 psf
(1594.89 kg/m3)

8.0” (203.2mm)


347.08 psf
(1694.59 kg/m3)

8.5” (215.9mm)


367.49 psf
(1794.24 kg/m3)

9.0” (228.6mm)


387.91 psf
(1893.94 kg/m3)

9.5” (241.3mm)


408.33 psf
(1993.64 kg/m3)

10.0” (254mm)


489.99 psf
(2392.34 kg/m3)

12” (304.8mm)


571.66 psf
(2791.09 kg/m3)

14” (355.6mm)


653.32 psf
(3189.79 kg/m3)

16” (406.4mm)


734.99 psf
(3588.54 kg/m3)

18” (457.2mm)


816.65 psf
(3987.24 kg/m3)

20” (508mm)


898.32 psf
(4385.98 kg/m3)

22” (558.8mm)


979.98 psf
(4784.68 kg/m3)

24” (609.6mm)


1,061.65 psf
(5183.43 kg/m3)

26” (660.4mm)

YAMATO class Battleship Turret Frontal Plate. Thickest piece of armor ever cast/rolled.

Historic .50 M2 AP V50 Protection Trends

References:
ARL-RP-8 October 2000 – Performance Metrics for Composite Integral Armor (2.5 MB PDF) specifically THIS image.

Ground Systems Integration Domain (GSID) Materials for Ground Platforms, 20 Sep 2010 (4.2 MB PDF), specifically THIS slide, which does not show a protection level, but you can figure it out as being for .50 M2 AP by looking at the all-titanium concept.

Material

Areal Density
(psf = Pounds Per Square Foot)

Actual Thickness of Plate

RHA Equivalent Thickness

RHA Steel

Aprox 58~ psf
(Approx 283.18~ kg/m3)

2.74” (69.6mm)

2.74” (69.6mm)

Aluminum

Approx 55~ psf
(Approx 268.53~ kg/m3)

4.72” (120mm)

2.74” (69.6mm)

Titanium

Approx 45~ psf
(Approx 219.71~ kg/m3)

3.01” (76.45mm)

2.74” (69.6mm)

Aluminum-Ceramic

40~ psf
(Approx 195.3~ kg/m3)

3.4” (86.36mm)

2.74” (69.6mm)

CAV-ATD
Composite Ceramics

Approx 25~ psf
(Approx 122.06~ kg/m3)

1.77” (44.96mm)

2.74” (69.6mm)

Baseline 20 psf
CAV Solution

Approx 20~ psf
(Approx 97.65~ kg/m3)

1.545” (39.24mm)

2.74” (69.6mm)

Baseline 20 psf
Aluminum-Foam Solution

Approx 20~ psf
(Approx 97.65~ kg/m3)

2.05” (52mm)

2.74” (69.6mm)

NOTES: The various Ceramic/Composite Armor systems are composed of the following systems:

  • Baseline 20 psf CAV Solution: (0.05” cover plate, 0.7” Al2O3, 0.125” Rubber, 0.67” S-2 Glass V/E)

  • Baseline 20 psf Aluminum-Foam Solution: (0.05” cover plate, 0.7” Al2O3, 0.75” Al-Foam, 0.55” S-2 Glass/VE)