Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
21CrMoV5-7 Hex Bolts (EN 10269 / 1.7709) Cr-Mo-V Q+T Bolting
21CrMoV5-7 hex bolts are full-body hex-head bolts machined from EN 10269 1.7709 Cr-Mo-V Q+T bar, supplied to DIN 931 / ISO 4014 standards in metric M12 to M64 and to ASME B18.2.1 in 1/2 inch to 2 1/2 inch. Standard fastener for general flange bolting, pump and valve service at metal temperatures to 550 deg C.
Hex Bolts Designs and Variants
Three head profiles: standard hex head (DIN 931 partial thread, DIN 933 full thread) for general bolting; heavy hex head (ASME B18.2.1) for pressure-vessel and flange bolting where extra bearing area is required (see heavy hex bolts); and structural hex head with hardness-matched bearing surface on call-out.
Size Range
| Standard | Diameter range | Length range |
|---|---|---|
| DIN 931 / ISO 4014 (partial thread) | M12 to M64 | 40 to 300 mm |
| DIN 933 / ISO 4017 (full thread) | M12 to M48 | 20 to 200 mm |
| ASME B18.2.1 hex bolts | 1/2 inch to 2 1/2 inch | 1 inch to 12 inch |
Mechanical Properties (Q+T, EN 10269)
| Property | Value | Condition |
|---|---|---|
| Tensile (Rm) | 700 to 850 MPa | RT, Q+T |
| 0.2 percent proof stress (Rp0.2) | ≥550 MPa | RT, Q+T |
| Elongation A5 | ≥16 percent | RT, longitudinal |
| Charpy V impact (KV) | ≥63 J | 20 deg C |
| 0.2 percent proof at 500 deg C | ≥450 MPa | elevated-temp |
| Hardness | 210 to 250 HBW | Q+T |
Standards Anchor
Manufactured to EN 10269 chemistry and mechanicals. Head and thread dimensions to DIN 931 / DIN 933 (metric) or ASME B18.2.1 (Unified inch). Thread pitch to ISO 261 (metric coarse) and ISO 262 (metric fine), or ASME B1.1 (UN, UNC, UNF). Dual-certification to ASTM A193 Grade B16 on call-out.
Companion Hardware
Matched-grade Cr-Mo-V companions ship from the same heat lot on call-out: 21CrMoV5-7 nuts, washers, threaded rod, stud bolts and round bar.
Applications
21CrMoV5-7 hex bolts are specified in: steam turbine bolting (LP/IP casings and steam-line flanges), power plant bolting (subcritical drum and steam-line flanges), pressure vessel bolting (per VdTUV Wb 350), boiler bolting (drum-head and steam-pipe flanges), and heat exchanger bolting (channel-head and shell-side flanges).
Inspection Documentation
Default delivery is EN 10204 type 3.1 mill test certificate with heat number, melt-shop pour record, chemistry to EN 10269 21CrMoV5-7, room-temperature tensile and 0.2 percent proof stress, elevated-temperature 0.2 percent proof at the design temperature, Charpy V impact at 20 deg C, hardness, full Q+T cycle chart and dimensional report tied to the heat lot. Type 3.2 with Lloyd's Register, DNV, BV, SGS or TUV witness inspection on call-out and standard practice on turbine and pressure-vessel procurement.
Frequently Asked Questions
Q. What diameter range do you supply 21CrMoV5-7 hex bolts in?
Metric M12 to M64 (coarse and fine pitch); Unified 1/2 inch to 2 1/2 inch (UNC and UNF). Larger sizes on call-out from forged blank.
Q. Is DIN 931 the same as ISO 4014?
Yes. DIN 931 (partial-thread hex bolt) is the German national standard for the same product specified internationally as ISO 4014. Both standards govern identical head and thread dimensions. Bolts ship dual-marked.
Q. What is the maximum service temperature for a 21CrMoV5-7 hex bolt?
550 deg C continuous metal temperature to EN 10269. Above 550 deg C the design steps up to Durehete 1055 (Alloy T41 / 1.7729) for Ti+B microalloyed creep performance.
Q. Do you supply matched-grade hex nuts in 21CrMoV5-7?
Yes. Matched-grade hex nuts to DIN 934 / ISO 4032 are supplied from the same heat lot. Heavy hex nuts to ASME B18.2.2 for pressure-vessel work. See the nuts page.
Related 21CrMoV5-7 Form Factors
Browse the full 21CrMoV5-7 form-factor range: Round Bar · Stud Bolts · Heavy Hex Bolts · Tap Studs · Body-Bound Studs · Anchor Bolts · U-Bolts · Threaded Rod · Nuts · Washers · Forgings. Back to the 21CrMoV5-7 Alloy Hub.
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