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 Nuts (EN 10269 / 1.7709) Cr-Mo-V Q+T Bolting
21CrMoV5-7 nuts are the matched-grade companion hardware to 21CrMoV5-7 studs and bolts. Machined from EN 10269 1.7709 Cr-Mo-V Q+T bar with proof load matched to the stud rating, supplied in DIN 934 / ISO 4032 (metric) and ASME B18.2.2 (Unified inch) standards.
Nuts Designs and Variants
Three standard styles: hex nut (DIN 934 / ISO 4032; standard height) for general flange bolting; heavy hex nut (ASME B18.2.2) for pressure-vessel and heavy-flange bolting where the larger across-flats matches a heavy hex bolt; thin hex nut / jam nut (DIN 936 / ASME B18.2.2 jam nut) for lock-nut applications on call-out.
Size Range
| Standard | Style | Diameter range |
|---|---|---|
| DIN 934 / ISO 4032 | Standard hex nut | M12 to M64 |
| DIN 6915 / ISO 7414 | Heavy hex nut metric | M12 to M64 |
| ASME B18.2.2 hex | Standard hex nut inch | 1/2 inch to 2 1/2 inch |
| ASME B18.2.2 heavy hex | Heavy hex nut inch | 1/2 inch to 4 inch |
| DIN 936 / B18.2.2 jam nut | Thin / jam nut | M12 to M64 |
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 for chemistry and mechanicals. Proof load matched to the companion 21CrMoV5-7 stud or bolt rating per the stud-nut compatibility tables in EN ISO 898-2 (metric) or ASTM A194 (Unified, when used as matched nut for ASTM A193 B16).
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 nuts are specified as matched-grade companion hardware on steam turbine bolting, gas turbine, pressure vessel, heat exchanger, fired heater and petrochem reactor projects.
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 is the proof load for a 21CrMoV5-7 hex nut?
Proof load is matched to the companion stud or bolt rating. For an M30 21CrMoV5-7 stud at the EN 10269 Rp0.2 minimum (550 MPa), the matching hex nut proof load is approximately 280 kN. Full table on EN 20898-2 / ISO 898-2.
Q. Is a heavy hex nut required for pressure-vessel bolting?
Generally yes for ASME pressure-vessel work. ASME B18.2.2 heavy hex nut has larger across-flats than the standard B18.2.1 hex nut, giving more bearing area under the nut on the gasket flange. European pressure-vessel work uses DIN 6915 heavy hex nut for the same reason.
Q. Do you supply nuts in lower-grade material when matched-grade is overkill?
No. The 21crmov57.com product range is matched-grade only. For projects where the nut grade can be lower than the stud grade, ASTM A194 grade 2H or grade 4 nuts ship from torqbolt.com separately.
Q. Are the nuts supplied phosphated for anti-galling?
Manganese phosphate to MIL-DTL-16232 or molybdenum-disulphide dry-film lubricant on call-out for high-temperature anti-galling. Standard finish is bare with light oil.
Related 21CrMoV5-7 Form Factors
Browse the full 21CrMoV5-7 form-factor range: Round Bar · Stud Bolts · Hex Bolts · Heavy Hex Bolts · Tap Studs · Body-Bound Studs · Anchor Bolts · U-Bolts · Threaded Rod · Washers · Forgings. Back to the 21CrMoV5-7 Alloy Hub.
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