What are the different types of fixtures?

Short Answer:

Fixtures are special devices used in mechanical workshops to hold and support the workpiece firmly during machining operations. Unlike jigs, fixtures do not guide the cutting tool. They are used for tasks like milling, turning, grinding, and welding where the machine controls the tool movement.

There are different types of fixtures designed for specific machines and operations. Common types include milling fixture, lathe fixture, drilling fixture, grinding fixture, welding fixture, and modular fixture. Each type helps in improving accuracy, safety, speed, and consistency during production work.

Detailed Explanation:

Different types of fixtures

In mechanical manufacturing, it is very important to hold the workpiece securely and correctly during machining. If the workpiece moves or vibrates, the final product may have wrong size or shape. To avoid such problems, fixtures are used.

A fixture is a work-holding device that ensures the part stays in the right position during machining. While it does not guide the cutting tool like a jig, it keeps the workpiece steady, aligned, and safe. Fixtures are used on various machines and each machine or operation may need a different type of fixture.

Let us now study the different types of fixtures based on their usage.

  1. Milling Fixture

A milling fixture is used on a milling machine to hold the workpiece tightly while the cutter moves across its surface.

Features:

  • Mounted on the machine table
  • Includes clamps, T-bolts, and locating pins
  • May support multi-directional cuts

Used in: Slot cutting, face milling, contouring

Advantage: Improves precision and supports repeated cuts

  1. Lathe Fixture

A lathe fixture is used to hold parts on a lathe machine, especially when the job cannot be held using standard chucks or centers.

Features:

  • Holds irregular or soft parts
  • Mounted on faceplates or special attachments
  • Ensures balanced rotation

Used in: Turning, threading, grooving

Advantage: Safe and accurate turning of complex parts

  1. Drilling Fixture

A drilling fixture holds the job in the right position on a drilling machine and ensures the hole is drilled at the correct spot.

Features:

  • Secures flat or round parts
  • Often includes drill bushings for extra accuracy
  • Fixed to the drill table

Used in: Batch drilling of multiple parts

Advantage: Prevents movement and gives repeated hole accuracy

  1. Grinding Fixture

A grinding fixture holds workpieces securely during operations on grinding machines like surface or cylindrical grinders.

Features:

  • Made with high precision
  • Allows smooth rotation or movement under the wheel
  • Holds delicate parts firmly

Used in: Surface grinding, cylindrical grinding, centerless grinding

Advantage: Achieves fine surface finish and size control

  1. Welding Fixture

A welding fixture is used to hold metal parts in correct position and angle while they are welded together.

Features:

  • Withstands high temperature
  • Made of strong and heat-resistant material
  • May include adjustable clamps

Used in: Assembling frames, pipes, and sheet metal parts

Advantage: Reduces distortion and improves welding quality

  1. Assembly Fixture

An assembly fixture helps in joining different parts together in a fixed sequence and alignment.

Features:

  • Includes locating pins and guides
  • Supports easy part positioning
  • Used in manual or semi-automatic assembly

Used in: Product fitting, electronics, and packaging

Advantage: Speeds up assembly and reduces mismatch

  1. Modular Fixture

A modular fixture is a flexible setup made of standard parts like plates, pins, clamps, and brackets that can be rearranged for different jobs.

Features:

  • Reusable and customizable
  • Saves time in designing new fixtures
  • Can be assembled quickly

Used in: Prototyping, short production runs

Advantage: Cost-effective for multiple job types

Conclusion

Fixtures are important tools that ensure workpieces are held securely during machining processes like milling, drilling, turning, grinding, welding, and assembly. The main types include milling fixture, lathe fixture, drilling fixture, grinding fixture, welding fixture, assembly fixture, and modular fixture. Using the correct fixture helps improve the quality, speed, safety, and accuracy of machining operations. They are essential in both small workshops and large manufacturing industries.