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TAPER PIN FEATURESTaper pins are arguably one of the simplest pin designs available, and along with dowel pins, are the oldest. Taper pins are turned from barstock to varying tolerances depending on the specification. This production technique is slower than the heading and grinding process used to manufacture dowel pins, and slower than rolling steel pins.

HOW TO MEASURE THE TAPEREASY INSTALLATION

EXTERNALLY THREADED INTERNALLY THREADEDTAPER PINS

Threaded taper pins are used in blind holes

Removal is achieved by screwing a nut down onto the threads

Internally Thread For use as a pull dowel

Standard taper pins are used as positioning components for

transmitting low torques

pound a punch or drive tool into small end To remove

Tap wi th a hammer to

insert

#1, #2, #3 ...or 63µ

MICROFINISHDESIGNATIONS TAPER

Taper pins are called out by a number and length

"I need a #3 by 2 inch"

The number refers to the diameter of the large end of imperial pins. To get the diameter of the small end, multiply the length by .02083 and subtract from the decimal size of the large end. See “Diameter Cross Reference,” page 249.

A 63 microfinish is standard to allow smooth insertion

ASME B18.8.2 specifies a taper of 1/4" per foot (0.02083" per inch)

63

Tapers are expressed in terms of rise over run. In other words, the amount of taper is stated per linear units of measure. A 1/4" taper per foot means that for every 12" in linear distance (run) the thickness of the part (rise) decreases by .25" (1:48). Metric pins decrease by 1 mm for every 50 mm (1:50).

Run

Rise

Design Considerations

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Page 251 Page 258 Page 264

TAPER PIN TYPES

To obtain diameter of small end (Y), multiply length (L) by .02083 and subtract from large end (X).

If a helically fluted taper reamer is used, the diameter of the small end of the pin is the size for the through drill.

Step drilling and using straight fluted reamers have specific requirements. Call for details.

Internal threads are used as an anchor for leverage during removal.

Simply designed pins that are hammered or driven into a tapered hole. 1/4" taper per linear foot.

External threads are used when a tapered pin has to be removed from the driven (large) end. Tightening a nut on the threads will unseat the pin.

Standard External Thread Internal Thread

DIAMETER CROSS REFERENCESTEP DRILLING TAPER PIN HOLES

Number Fractional Diameter

(Reference Only)

Decimaldiameter

#7/0 1/16" .063"

#6/0 5/64" .078"

#5/0 3/32" .094"

#4/0 7/64" .109"

#3/0 1/8" .125"

#2/0 9/64" .141"

#0 5/32" .156"

#1 11/64" .172"

#2 3/16" .193"

#3 7/32" .219"

#4 1/4" .250"

#5 19/64" .289"

#6 11/32" .341"

#7 13/32" .409"

#8 1/2" .492"

#9 19/32" .591"

#10 23/32" .706"

#11 55/64" .860"

#12 1-1/32" 1.032"

#13 1-15/32" 1.241"

#14 1-33/64" 1.523"

3rd

X

Y

2nd1st L

Design Considerations

ALWAYS TEST STEP-DRILLED

HOLES FOR VERIFICATION

PRIOR TO PRODUCTION

Step Drilled HOle Installed Pin

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QUICK REFERENCE GUIDE

Appl ications

Taper Pins are used to align and hold assembly Components toge ther

Common Names

Applicable Standards

Fabrication How to Identify

Common Uses

Comments

Taper Pin ASME B18.8.2 , MS 24692, AN 386, DIN 1, DIN 7977 (external thread); DIN 7978 (internal thread)

Not applicable to Standard Taper Pins sizes #11 – #14

Turning, thread rolling (if threaded)

Nominal diameter × nominal length; The nominal diameter of imperial pins is called out by a number used to signify the dimension.

Low torque positioning and locking. Often found on printing presses and other large mechanical assemblies. Mostly used in original equipment.

The diameter of imperial pins is measured at the large end. Metric pins are measured at the small end.T

ap

er

Taper pins are a highly precise locating pin. The taper causes constant contact through the length of the pin as well as the entire cross section creating exceptional holding power. It also allows for a repeatable firm seat and exact location when reinserted after disassembly.

External Threaded Taper Pins are used to Hold a clock Hand

Mechanism Together

Internal Threaded Taper Pins are Used in applications where a flush

surface is desired

TAPER PIN USE

EXTERNAL THREADED TAPER PIN USE INTERNAL THREADED TAPER PIN USE