M68×6.0 Thread Specifications
Complete dimensions for M68×6.0 coarse pitch thread per ISO 724. Pitch: 6.0mm (4.2 TPI equivalent).
Thread Dimensions
| Designation | M68×6.0 |
| Thread Series | ISO Metric Coarse |
| Pitch | 6.0 mm (4.2 TPI) |
| Major Diameter (d) | 68 mm (2.6772") |
| Pitch Diameter (d₂) | 64.103 mm (2.5237") |
| Minor Diameter — External (d₁) | 60.6386 mm (2.3873") |
| Minor Diameter — Internal (D₁) | 61.505 mm (2.4215") |
| Thread Depth | 3.2476 mm |
| Tensile Stress Area | 3013.01 mm² |
| Fundamental Triangle Height (H) | 5.1962 mm |
Tap Drill Size
Recommended tap drill: 62.0 mm
Calculated minor diameter (D₁): 61.51 mm. Closest standard metric drill: 62.0 mm.
Closest inch drill: 1/1" (1.0" / 25.4 mm)
Proof Loads by Property Class
| Class | Proof Stress (MPa) | Tensile Strength (MPa) | Proof Load (kN) | Tensile Load (kN) |
|---|---|---|---|---|
| 4.6 | 225 | 400 | 677.9 | 1205.2 |
| 4.8 | 310 | 420 | 934.0 | 1265.5 |
| 5.8 | 380 | 520 | 1144.9 | 1566.8 |
| 8.8 | 580 | 800 | 1747.5 | 2410.4 |
| 9.8 | 650 | 900 | 1958.5 | 2711.7 |
| 10.9 | 830 | 1040 | 2500.8 | 3133.5 |
| 12.9 | 970 | 1220 | 2922.6 | 3675.9 |
Proof load = stress area × proof stress. Per ISO 898-1.
Common Applications
- Structural steel
- Bridge construction
- Heavy industrial equipment
- Foundation bolts
How M68×6.0 Dimensions Are Calculated
All dimensions on this page are calculated from ISO 724 formulas using the nominal diameter (68 mm) and pitch (6.0 mm):
- Fundamental triangle height: H = (√3/2) × P = 5.1962 mm
- Pitch diameter: d₂ = d − 0.6495 × P = 64.103 mm
- Minor diameter (external): d₁ = d − 1.2269 × P = 60.6386 mm
- Minor diameter (internal): D₁ = d − 1.0825 × P = 61.505 mm
- Thread depth: 5H/8 = 3.2476 mm
- Tensile stress area: Aₛ = (π/4) × ((d₂ + d₃)/2)² = 3013.01 mm²