Turning/ Lathes

The lathe is available in many forms as listed below. All lathes are based upon thecentre lathe as shown in the figure below;
The basic operations that can be carried out on lathes include:-Turning, Facing, Boring, Drilling, Reaming, Counterboring, Countersinking, Threading,Knurling and Parting.

Centre lathes Engine lathes, Bench lathes, Toolroom lathes, Speed lathes, Duplicating lathes, Production lathes, Vertical lathes, Capstan/Turret lathes Automatic lathes

All of the important features of the lathe are shown on the above figure.
The headstock spindle which is hollow to allow bar stock to be fed through is generally provided with a special male thread to allow chucks etc. to be easily fitted and removed. Some of the different work holding units which can be fitted onto the headstock spindle are shown below.


Important Centre Lathe Dimensions

Face ..top surface of cutting tool Cutting Edge ..The part of the cutting tool which actually cuts the metal comprises the side cutting edge and the end cutting edge Flank ..The side of the cutting tool below the side cutting edge Nose ..Point to the tool Nose Radius ..The radius of the nose - 0,4mm for heavy cuts ,0,4-1,5mm for finishing cuts Nose Angle ..Plan angle between the side cutting edge and the end cutting edge Side Cutting Edge angle ..Angle between the side cutting edge and the line of the shank side End cutting edge angle ..Angle between the end cutting edge and a line drawn 90o to the shank side Side Relief/clearance Angle ..The angle between the tool flank and the original side of the tool End Relief/clearance Angle ..The angle between the end of tool and a line drawn 90o to the Centre line of the Lathe Side Rake ..Angle between the tool face and the horizontal Plane parallel to the axis of the lathe Back Rake Rake ..Angle between the tool face and the horizontal Plane 90o to the axis of the lathe

The cutting speed is the speed at which the work surface passes the cutting tool. This is mainly dependent on the material being turned and the cutting tool material. The table below indicates some approximate cutting speed for turning on a lathe.

For information on cutting materials refer Cutting Materials. For information on cutting fluids refer Cutting Fluids

Material	Cutting Tool Material	Rough Cut	Finishing Cut
		m/min	m/min
Free Cutting Steel	H.S.S	35	90
	Cast Alloy	75	145
	Carbide	125	205
Low Carbon Steel	H.S.S	31	80
	Cast Alloy	65	130
	Carbide	106	190
Medium Carbon Steel;	H.S.S	30	69
	Cast Alloy	58	107
	Carbide;	92	152
High Carbon Steel	H.S.S	24	61
	Cast Alloy	53	91
	Carbide	76	137
Cast Iron Grey	H.S.S	24	41
	Cast alloy	43	76
	Carbide	69	125
Brass / Bronze Free Cutting	H.S.S	53	110
	Cast Alloy	105	170
	Carbide	175	275
Aluminium	H.S.S	40	90
	Cast Alloy	55	115
	Carbide	75	185
Plastics	H.S.S	30	75
	Cast Alloy	45	115
	Carbide	60	150

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