Screwed mandrel

Screwed mandrel
This mandrel is threaded at one end and has a collar.
It is used to hold workpieces having threaded holes.

Step mandrel
Step mandrel has step of different sizes of
holes.

Collar mandrel
This mandrel has two collars.
Collars fit firmly into the hole of workpiece.
Collar mandrel is lighter in weight.
It is used for holding workpieces having larger diameter
holes.

MILLING FIXTURE
Location – Machine Table
Use – For Clamping Workpiece
Should be Strong and Rigid
Clearance should be provided for
disposal of swarf

Elements of Milling Fixture
Base
Tenon Strip
Setting Block
T – Bolts
Clamping Device
Locating and Positioning element

Base
Thickness 20-25mm
Should be Rigid, absorb cutting forces
Material used – Cast Iron
Tenon Strip
Locate fixture base with reference to milling cutter
Fixes the base of the fixture to machine table in
same relative position every time
Material used – hardened and ground steel
Setting block
With the help of Feeler gauge(used to check positional accuracy)
Use – reduces time for setting milling cutter relative to fixture
Material used – hardened and ground steel

T – bolts
Use – binds fixture to mill table
Clamping Device
Should be rigid
Must not loosen by vibration caused during cutting
Must not interfere during cutting operation
Locating and positioning element
Cylindrical locating pins, diamond locators

Different types of milling
Single Piece Milling
String Milling
Reciprocal Milling
Progressive Milling
Index Milling
Rotary Milling

Dimensional Data of Milling
Dimensions of Milling Machine table
Dimensions of T – Slots
Center to Center distance of T – Slots
Length of Travel in all three fed directions

Strap Clamps
Used for holding the fixture bases(fixture to be used on
more than one machine)
Should be extremely rigid
Should be tight even during more vibrations