High Strength Steel (HSS) Used In NISSAN Vehicles

WARNING: This page is about a different car, the 2007 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

HIGH STRENGTH STEEL (HSS) USED IN NISSAN VEHICLES

Tensile strength	Nissan/Infiniti designation	Major applicable parts
373 N/mm² (38kg/mm² , 54klb/sq in)	SP130	Front inner pillar upper Front pillar hinge brace Outer front pillar reinforcement Other reinforcements
785-981 N/mm² (80-100kg/mm² 114-142klb/sq in)	SP150	Outer sill reinforcement Main back pillar
SP130 is the most commonly used HSS. SP150 HSS is used only on parts that require much more strength.

Read the following precautions when repairing HSS:

Additional points to consider
- The repair of reinforcements (such as side members) by heating is not recommended since it may weaken the component. When heating is unavoidable, do not heat HSS parts above 550°C (1,022°F).
  Verify heating temperature with a thermometer.
  
  (Crayon-type and other similar type thermometer are appropriate.)
  
  Fig 1: Applying Heat On Side Member
- When straightening body panels, use caution in pulling any HSS panel. Because HSS is very strong, pulling may cause deformation in adjacent portions of the body. In this case, increase the number of measuring points, and carefully pull the HSS panel.
  
  Fig 2: Caution - Pulling HSS Panel
- When cutting HSS panels, avoid gas (torch) cutting if possible. Instead, use a saw to avoid weakening surrounding areas due to heat. If gas (torch) cutting is unavoidable, allow a minimum margin of 50 mm (1.97in).
  
  Fig 3: Caution - Cutting HSS Panels
- When welding HSS panels, use spot welding whenever possible in order to minimize weakening surrounding areas due to heat.
  If spot welding is impossible, use M.I.G. welding. Do not use gas (torch) welding because it is inferior in welding strength.
  
  Fig 4: Caution - Welding HSS Panels
- The spot weld on HSS panels is harder than that of an ordinary steel panel.
  Therefore, when cutting spot welds on a HSS panel, use a low speed high torque drill (1,000 to 1,200 rpm) to increase drill bit durability and facilitate the operation.
- SP150 HSS panels with a tensile strength of 785 to 981 N/mm² (80 to 100 kg/mm² , 114 to 142 klb/sq in), used as reinforcement in the door guard beams, is too strong to repair. When these HSS parts are damaged, the outer panels also sustain substantial damage; therefore, the assembly parts must be replaced.
  
  Fig 5: Caution - Drilling HSS Panels

Precautions in spot welding HSS

This work should be performed under standard working conditions. Always note the following when spot welding HSS:

The electrode tip diameter must be sized properly according to the metal thickness.

Fig 6: Caution - Welding HSS
The panel surfaces must fit flush to each other, leaving no gaps.

Fig 7: Identifying Correct Position Of Flushing Panel Surfaces

Follow the specifications for the proper welding pitch.

THICKNESS SPECIFICATION

Unit: mm
Thickness (t)	Minimum pitch (l)
0.6 (0.024)	10 (0.39) or over
0.8 (0.031)	12 (0.47) or over
1.0 (0.039)	18 (0.71) or over
1.2 (0.047)	20 (0.79) or over
1.6 (0.063)	27 (1.06) or over
1.8 (0.071)	31 (1.22) or over

Fig 8: Identifying Proper Welding Pitch