# DIN 931 vs DIN 933 Hex Bolts: What Is The Difference?

When purchasing industrial fasteners, many buyers confuse DIN 931 and DIN 933 hexagon head bolts. Both are popular DIN standard steel bolts, available in Grade 8.8 and Grade 10.9, but their thread designs and application scenarios are totally different.

## DIN 931: Semi-Threaded Hexagon Head Bolts

DIN931 bolts are **semi-threaded**. Only part of the shank has threads; a smooth unthreaded section remains under the bolt head.

✅ Best use cases:

Structural connection, heavy load assembly, machinery frames, steel structure projects.

The smooth shank provides stronger shear resistance, ideal for heavy static loads.

## DIN 933: Full-Threaded Hexagon Head Bolts

DIN933 bolts are **fully threaded**. Thread runs along nearly the entire bolt length.

✅ Best use cases:

General equipment assembly, thin plate connection, adjustable fastening.

Suitable when you need flexible nut positioning for thinner workpieces.

## Quick Comparison Table

| Item | DIN931 | DIN933 |

| ---- | ---- | ---- |

| Thread type | Partial / semi threaded | Full threaded |

| Strength | Grade 8.8 / 10.9 steel | Grade 8.8 /10.9 steel |

| Surface option | Zinc plated | Zinc plated |

| Best for | Heavy load structural joint | General thin part assembly |

## How To Choose Between Grade 8.8 and Grade10.9

- Grade 8.8: General industrial use, good balance of strength & cost.

- Grade10.9: High tensile strength, for heavy-duty, high-pressure equipment.

## Where To Buy DIN Standard Hex Bolts Wholesale

We supply wholesale DIN standard hexagon head bolts, including DIN931 and DIN933, Grade 8.8 and 10.9 zinc plated steel fasteners. OEM & custom sizes available for bulk orders.

Internal links:

- DIN Standard Hexagon Head Bolts Grade 8.8 10.9

- Fasteners Category