enlarge previouslyA reamer is a rotary cutting tool used to*

REAMERSREAMERSenlarge previously A reamer is a rotary cutting tool used to *

holes to accurate dimensions. bored or drilled

l flutes in the helicaor straightReamers may have two or more * body.

* There are several different types of reamers.

shankand thebody* The main parts of a reamer are the shankand the body The main parts of a reamer are the

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TYPES OF REAMERS

M hi1. Machine reamers

2. Hand reamersMachine Reamers :

Machine or chucking reamers are available in a wide variety of types and sizes .and sizes .

These reamers are supplied either with straight shanks or with tapered shanks.

considered to be roughing tools and are :Rose chucking reamers. 1used where the hole finish and accuracy are not critical.

have more teeth than rose reamers for:Fluted chucking reamers2 have more teeth than rose reamers for :Fluted chucking reamers. 2the same diameter and are considered to be finishing tools primarily.

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Rose chucking reamersRose chucking reamers

Fluted chucking reamers

: have longer teeth than chuckling . Jobber's reamers3reamers

: used for roughing operation.Fluted shell reamers4

a/v in solid and adjustable types

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: this reamer can be . The expansion reamer5expanded and resharpened to its original size several times.

: HSS or CarbideThe adjustable chucking reamer6 : HSS or Carbide . The adjustable chucking reamer6blades can be replaced individually or sets.

: developed for the . The Carbide tipped reamer7need of higher production rates.g p

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Hand Reamers :

High-speed steel or carbon steel and with straight or helical teeth.High speed steel or carbon steel and with straight or helical teeth.

purpose reamers used for -are generaltype hand reamers-Solid. 1most standard hole sizes.

Reamer Care1. Never turn a reamer backward at any time, since this will ruin the cutting edges.2. Always store reamers in separate compartments. If stored in the same

container they must be separated by some suitable material such ascontainer, they must be separated by some suitable material such as cardboard, plastic, or wood.

3. Never roll, drop, or place reamers on the metal surfaces of benches or machines.

4. Always use the proper speed when reaming.5. Never feed a reamer too fast. This may cause it to jam in the work.6. Use the proper cutting fluid for the metal being reamed.7 Never permit a reamer to chatter This will dull the cutting edges quickly7. Never permit a reamer to chatter. This will dull the cutting edges quickly.8. Use helical-fluted reamers for deep holes or holes which have keyways or

grooves.

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REAMING FACTORS1. The type of work material2 Th i idit f th t2. The rigidity of the setup 3. The use of the correct cutting fluid 4. The depth of the hole5. The type and condition of the reamer yp6. The condition of the machine7. The type of finish required

Stock AllowanceThere is no definite rule for the amount of stock to be left on the hole diameter for reaming because of the many factors which must be considered.

Reaming SpeedThe speed at which the hole is reamed depends mainly on the type of material being machined and the diameter of the reamer. g

of the speed used thirds-about twoThe reaming speeds for most materials are for drilling.

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TAPS

# Used to produce internal threads

# Th d ill b d f ith# The drill press may be used for either hand or machine tapping

# Hand tapping is generally used when only a few holes are to be tapped. pp

# Machine tapping is preferred when many h l t b t dholes must be tapped.

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TYPES OF TAPS:) Hand Taps1( : ) Hand Taps1(

are available in sets containing three taps:

Taper, p ,

, andPlug

Bottoming.

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:) Machine Taps2(

used with power

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Tap Drill Size (TDS):

INCH :

Q. Calculate the tap drill size required for a 1-in. -8 NC thread.

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Metric TapsMetric taps are identified with the letter M followed by the nominal diameter of the thread in millimeters times the pitch in millimeters.

Tap Drill Sizes for Metric ThreadsThe tap drill sizes for metric threads may be calculated by subtracting the pitch from the nominal diameter.T.D.S. = D-P

For example: Calculate the tap drill size for an M12 X 1.75 thread.

T.D.S. = 12 - 1.75 = 10.25 mm

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