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Reamer and types

The function of a reamer is to produce a smooth accurate surface in a bore such as that of a bearing or bush, for the shaft, pin or bolt to enter with a very good fit. In engine room Reamers are used for
  • The stern tube hole in stern frame is cast/fabricate roughly under size. When Main Engine is aligned with centre line of the stern frame hole, this hole is reamed to required diameter to fit the stern tube.
  • Fitted bolts on rudder palm and rudder carrier bearing housing for the press fit. They are to be reamed to exact diameter to avoid relative movement.
  • If a hole is drilled for internal threads then before we start with the procedure of making threads (tapping) we have to make sure we get a smooth finish for the threads.
In this respect, a reamer is a much better tool than a drill and can also produce finishes superior to normal machining on lathes. In fact, bores machined on lathes are often finished with reamers to improve the surface and bring them to size. Holes to be reamed must be drilled or machined undersize, the amountof material left depending on the roughness of the surface. Reamers are reaming tools which can be used on lathe machine for drilling purpose.
Total 8 types of reamers are- Adjustable hand reamer, Straight reamer (precision), Hand reamer, Machine reamer, Shell reamer, Tapered reamer, Morse taper reamer & combination reamer.
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