Ramor 550 is SSAB’s extra‑high‑hardness quenched ballistic‑protection steel. Its core advantage lies in weight reduction: at equal ballistic‑protection performance, thinner Ramor 550 plate can replace Ramor 500, cutting cabin‑armour weight by 10‑20 %. This substantial weight saving improves vehicle payload capacity, fuel efficiency and cross‑country mobility. According to SSAB, Ramor 550 provides around six‑times the hardness and strength of ordinary mild structural steel such as S355, while delivering best‑in‑class workshop processability within its hardness bracket, comparable to Ramor 500.
Core Features
Weight‑saving ballistic‑protection grade: 10‑20 % lighter than Ramor 500 for identical threat‑stopping capability
Extra‑high hardness range: 540‑600 HBW, quenched ready‑to‑use, no extra heat‑treatment required
Balanced machinability: Best fabricating performance among steels of this hardness level
Wide application coverage: Armoured‑vehicle hulls, military platforms, safe‑room shelters, marine‑security and banking‑vault reinforcement
Mechanical Properties
Official Guaranteed Delivery Values
|
Parameter |
Specification |
|
Available Thickness Range |
3.0 – 15.0 mm (sheet: 3.0‑6.0 mm; plate: 6.0‑15.0 mm) |
|
Brinell Hardness HBW |
540 – 600 |
|
Delivery Condition |
Quenched |
|
Maximum Service Temperature |
≤ 180°C; ballistic performance no longer guaranteed above this temperature |
Typical Mechanical Values
|
Parameter |
Typical Value |
|
Yield Strength Re |
1550 MPa |
|
Tensile Strength Rm |
1850 MPa |
|
Elongation A5 |
7 % |
|
Typical Hardness |
570 HBW |
|
Charpy V‑Notch Impact Energy (‑40°C) |
16 J |
Hardness inspection carried out per EN ISO 6506‑1 on a milled surface 0.3‑2.0 mm below plate surface, tested for each heat‑treatment batch or coil. Acceptance shall follow the mill‑issued EN 10204 3.1/3.2 MTC certificate.
Physical Properties (Ramor‑Series Typical Values)
|
Parameter |
Typical Value |
|
Density |
7.67 – 7.86 kg/dm³ (≈ 7.85 kg/dm³) |
|
Elastic Modulus |
190 – 210 GPa |
|
Poisson’s Ratio |
0.27 – 0.30 |
Chemical Composition (Heat Analysis, Max. wt %)
|
Grade |
C |
Si |
Mn |
P |
S |
Cr |
Ni |
Mo |
B |
|
Ramor 550 |
≤ 0.36 |
≤ 0.70 |
≤ 1.50 |
≤ 0.015 |
≤ 0.010 |
≤ 1.50 |
≤ 2.50 |
≤ 0.80 |
≤ 0.005 |
Fine‑grained aluminium‑killed steel. Phosphorus and sulphur are non‑intentional residual elements. Elevated carbon, chromium, nickel and molybdenum contents deliver its extra‑high‑hardness performance range of 540‑600 HBW.
Size & Thickness Tolerance
Cut‑to‑length Sheet (3.0‑6.0 mm)
|
Thickness (mm) |
Thickness Tolerance (mm) |
|
3.00 – 4.00 |
0 / +0.36 |
|
4.01 – 5.00 |
0 / +0.40 |
|
5.01 – 6.00 |
0 / +0.42 |
Medium‑Heavy Plate (6.0‑15.0 mm)
|
Thickness (mm) |
Thickness Tolerance (mm) |
|
6.0 – 7.9 |
0 / +0.8 |
|
8.0 – 15.0 |
0 / +1.0 |
Length & width tolerance: Sheet to EN 10051, heavy plate to EN 10029 or SSAB agreed specification
Flatness: ≤ 6 mm / 1000 mm (surpasses EN 10029 Grade N Class L and EN 10051)
Surface quality: EN 10163‑2 Class B, Sub‑class 3
Delivery state: Quenched
Ballistic‑Protection Minimum‑Thickness Reference
EN 1522 / PM2000 Standard
|
Protection Level |
Threat Ammunition |
Min. Ramor 550 Thickness (mm) |
|
FB4+ |
7.62×39 AK47 (M43) |
3.7 |
|
FB5 / FB6 |
5.56×45 SS109 / 7.62×51 NATO Ball |
5.9 |
|
FB7 |
7.62×51 NATO AP Armour‑Piercing |
13 |
NIJ 0108.01 Standard
|
Protection Level |
Threat Ammunition |
Min. Ramor 550 Thickness (mm) |
|
Level III |
7.62×51 NATO Ball |
5 |
|
Level IV |
.30 M2 AP Armour‑Piercing |
13 |
Processing & Usage Guidelines
Heat‑treatment: Supplied quenched. No re‑heat‑treatment permitted. Ballistic properties are invalid above 180 °C.
Cold‑bending: Minimum inside bend radius = 6 × plate thickness (both directions), matching Ramor 500. Recommended die opening ratio W/t = 16‑20.
Bending force: Bending‑force requirement approximately +10 % higher than Ramor 500 at equal thickness; allow extra machine capacity margin during equipment selection.
Spring‑back compensation: At 90° bend with R/t = 6, spring‑back angle exceeds Ramor 500 / 450; compensation is required (≈ 30° spring‑back for 6 mm plate, W/t = 18).
Cutting: Laser, plasma and water‑jet cutting are suitable. Water‑jet cutting is preferred for preserving ballistic edge integrity. Mechanical shearing requires heavy‑duty equipment and hardened cutting blades.
Welding: Conventional welding processes applicable. Austenitic consumables recommended: GMAW solid wire EN 12072 G 18 8 Mn / AWS A5.9 ER307; SMAW electrode EN 1600 E 18 8 Mn B 4 2 / AWS A5.4 E307‑15. Pre‑heating study is mandatory when ferritic filler metals are used.
Machining: Use carbide‑tipped cutting tools, rigid workpiece clamping, sufficient lubrication and anti‑vibration setup.
Work‑site safety: Cutting and grinding operations produce fine steel dust; suitable respiratory‑protection equipment must be worn.
Typical Applications
Armoured‑vehicle body panels, hull sections and door structures
Military vehicles and defence‑equipment components
High‑performance safe‑room shelters and mobile security cabins
Marine‑vessel ballistic‑protection structural parts
Bank counters, vault reinforcement and currency‑exchange booths
Shooting‑range safety barriers and equipment
Ramor‑Series Grade‑Selection Overview
|
Grade |
Thickness (mm) |
Hardness HBW |
Yield Strength Re (MPa) |
Product Positioning |
|
Ramor 300 |
3.0‑6.0 |
260‑320 |
820 |
Low‑hardness steel for low‑threat civilian‑protection |
|
Ramor 400 |
2.0‑30.0 |
360‑460 |
1100 |
Medium‑hardness grade, blast‑and‑ballistic balanced, best fabricability |
|
Ramor 450 |
8.0‑16.0 |
400‑480 |
1200 |
Medium‑hardness armour, ballistic‑performance plus high‑impact‑toughness |
|
Ramor 500 |
2.0‑30.0 |
490‑560 |
1450 |
Main‑stream high‑hardness ballistic‑protection grade, full‑thickness‑range coverage |
|
Ramor 550 |
3.0‑15.0 |
540‑600 |
1550 |
Extra‑high‑hardness, top‑choice for weight‑reduction upgrade, best machinability within hardness bracket |
|
Ramor 600 |
3.0‑6.0 |
Nominal 600 |
1650 |
Ultra‑high‑hardness thin ballistic plate; consult SSAB for detailed‑processing parameters |
Request official Ramor 550 datasheet, ballistic‑test documentation, EN 10204 3.1/3.2 inspection certificates and custom cutting‑to‑size service for your lightweight armoured‑structure projects.
Disclaimer: All technical data are sourced from official SSAB documentation, for reference‑only design guidance. Final product acceptance is governed exclusively by the mill‑issued MTC certificate.
