Page #3 #2 Micrometer Quiz Tyco Norwood --- Safety --- The Decimal Number System --- 6 Scale --- Micrometer --- Blueprint Reading --- Metric > Inch Conversion --- Tolerance Calculations --- The Unified Screw Thread --- Using The Decimal Equivalent Chart --- Standard Drill Sets --- Micro Finishes
Page #2 Machine Shop Safety Safety Glasses Everyone must wear safety glasses in the shop. Even when you're not working on a machine, you must wear safety glasses. Clothes and Hair Check your clothes and hair before you walk into the shop. If you have long hair tie it up. If your hair is caught in spinning machinery, it will be pulled out if you're lucky. If you're unlucky, you will be pulled into the machine. No Loose baggy clothing. Ex: No Gloves and no Jewelry Wear appropriate shoes Always be aware of the oily condition of the floor aroun your machine and Assigned work area. No open toe sandals. Wear shoes that give a sure footing. If you are working with heavy objects, steel toes are re commended. Safe Conduct in the Shop Be aware of what's going on around you. Listen to the machine, If something doesn't sound right, turn the machine off. Do not let someone else talk you into doing something dangerous. Do not attempt to measure a part that's moving. Never touch chips or rotating tooling with your hands or fingers when a machine running. Keep the shop doors closed. Do not let any unauthorized people in the shop. "No access card, No admittance" is the policy. Machining If you do not know how to do something, ASK! Before starting the Machine: Study the machine, Know which parts move, which are stationary, and which are sharp. Remove wrenches from area s of low machine clearance. Pull chips at the end of your shift. Do not use compressed air to blow machines clean. This endangers people's eyes and can force dirt into machine slides. Never pull or remove chips with your bare hands. Never operate machinery alone in the shop. Hazardous Waste Always follow proper guidlines when disposing of Hazardous Waste. If your not sure what is proper, ask your team leader for help.
Page #3 Decimal Numbering System Whole Numbers Decimal Numbers ½ ¼ ¾ ½.0 Thousandths. Thousandths.2 Thousandths Millions Hundred - Thousands Ten - Thousands Thousands Hundreds Tens Ones.... Tenths 0 5 2 7 5 Hundredths 5 5 0 Thousandths 0 0 2 Ten - Thousandths Hundred - Thousandths Millionths.750.400.200.50 2.00.75 TOLERANCES REVISIONS.X +/-.XX +/-.00.XXX +/-.002 ANGLES +/- FINISH UNLESS OTHERWISE SPECIFIED Number FROM 2 3 4 5 6 DATE Number FROM 2 3 4 5 6 DATE DRAWN RM CHECKED PREV.DWG. DATE SCALE FULL APPROVED SUPERSEDED NAME MATERIAL SHOP ORDER NUMBER PART NUMBER DRAWING NO.
Page #4 The Steel Rule The steel rule is the most common and basic measuring tools found in the machine shop. The rule (sometimes called a scale) is available in many different combinations or sets of division. The most common one used is divided into four increments of measurement by 64ths, 32nds, 6ths, and 8ths as shown below. /8" 6 8 2 /6" Front /32" 32 64 2 /64" Back Please answer the following questions;. How many 64ths are there in one inch? 2. How many 32 ths are there in one inch? 3. How many 6 ths are there in /4 of an inch? 4. How many 8 ths are there in 3/4 of an inch? 5. How many 64 ths are there in 3/4 of an inch?
Page #5 Reading The Steel Rule Students Name Please write in the correct scale measurements as indicated below. 2 3 2 3
Page #6 Reading The Steel Rule Students Name Please write in the correct scale measurements as indicated below. A B C D E F G 2 3 H I J K A = B = C = D = E = F = G = H = I = J = K = AA EE DD CC BB AA = BB = CC = DD = 2 3 EE = FF = GG = FF GG KK HH = II = HH JJ = I I KK = JJ
Page #7 Reading The Steel Rule Students Name Please write in the correct line length measurements indicated below. Your answer should be written to the nearest /6 " reduced to it's lowest terms. 2 3 4 6 7 5 8 9 0 2 3 6 4 5 8 7 9 20
Page #8 Reading The Steel Rule Students Name Please write in the correct measurements between arrowheads as indicated below. Your answer should be written to the nearest /6 " reduced to it's lowest terms.
Page #9 Exercise in Reducing Fractions. Reduce the following common fractions to decimals. ¼ 7/8 5/8 3/32 3/8 3/6 /64 3/64 2/3 9/0 /25 /6 4/5 3/32 63/64 9/32 2. Please find the total of the following sets of numbers..250.25.375 2.5625 9/32 3/32 5/64.500.9375.750 63/64 3 7/32 0.476" X Z.602".47" 0.844" Please Calculate the correct values for dimension 'X' and 'Z'.65" 2.23" 3.089" 4.292"
Page #0 The Parts of a Micrometer Anvil Spindle Sleeve Each Graduation Equals.025 Thimble Each Graduation Equals.00 Ratchet 0 2 5 0 Frame This Micrometer Reading =.279.200.075.004 ----------.279
Reading The Micrometer 0 2 5 2 3 4 0 0 5 Reading = Reading = 5 6 7 5 0 2 5 0 0 Reading = Reading = 6 7 8 0 0 2 5 20 0 Reading = Reading = 0 0 0 2 0 5 20 Reading = Reading = 0 2 20 7 8 9 20 5 5 Reading = Reading = 3 4 5 5 2 3 0 0 20 Reading = Reading = Page #
. Please fill-in the correct names of the micrometer in the drawing below. A -- B -- C -- D -- E -- 0 2 5 0 F -- 2. What is the range of any micrometer? 3. How many threads per inch are there on item 'B' shown above? 4. What is the value of each line on the item marked 'C' in the above drawing? 5. What is the value of each numbered line on the item marked 'C' in the above drawing? 6. What is the value of each line on the item marked 'D' in the above drawing?
5 Un-Scanned Pages Micrometer Readings
PAGE ONE OF BLUEPRINT READING CURRICULUM TITLE BLOCK ONLY NOTES:. MAT'L. = STAINLESS STEEL PER ASTM-A484 AND ASTM-A582 TYPE 303 2. UNLESS OTHERWISE SPECIFIED, HOLES, SLOTS, & DIAMETERS, SHALL BE PARALLEL AND CONCENTRIC WITHIN.003 T.I.R. 3. FINISH TO BE 63 UNLESS OTHERWISE SPECIFIED. 4. REMOVE BURRS AND BREAK SHARP CORNERS (.005 RAD. MAX.). USED ON UNLESS OTHERWISE SPECIFIED ALL DIMENSIONS ARE INCHES, AND BEFORE PLATING. ALL ANGLES ARE DEGREES TOLERANCES FRACTIONS DECIMALS ANGLES + + /64 + - -.005 deg - DRAWN DATE CHECKED APPROVED TITLE SIZE CODE IDENT NO COND REV
ISOMETRIC VIEW.000" ISOMETRIC VIEW ----------------------- ALL SQUARE & RECTANGULAR BLOCKS HAVE 6 SIDES. 2.000" 3.000" NOTES:. MAT'L. = STAINLESS STEEL PER ASTM-A484 AND ASTM-A582 TYPE 303 2. UNLESS OTHERWISE SPECIFIED, HOLES, SLOTS, & DIAMETERS, SHALL BE PARALLEL AND CONCENTRIC WITHIN.003 T.I.R. 3. FINISH TO BE 63 UNLESS OTHERWISE SPECIFIED. 4. REMOVE BURRS AND BREAK SHARP CORNERS (.005 RAD. MAX.). USED ON UNLESS OTHERWISE SPECIFIED ALL DIMENSIONS ARE INCHES, AND BEFORE PLATING. ALL ANGLES ARE DEGREES TOLERANCES FRACTIONS DECIMALS ANGLES + + /64 + - -.005 deg - DRAWN DATE CHECKED APPROVED TITLE SIZE CODE IDENT NO COND REV
ISOMETRIC VIEW.000" ISOMETRIC VIEW ----------------------- ALL SQUARE & RECTANGULAR BLOCKS HAVE 6 SIDES. 2.000" 3.000" NOTES:. MAT'L. = STAINLESS STEEL PER ASTM-A484 AND ASTM-A582 TYPE 303 2. UNLESS OTHERWISE SPECIFIED, HOLES, SLOTS, & DIAMETERS, SHALL BE PARALLEL AND CONCENTRIC WITHIN.003 T.I.R. 3. FINISH TO BE 63 UNLESS OTHERWISE SPECIFIED. 4. REMOVE BURRS AND BREAK SHARP CORNERS (.005 RAD. MAX.). USED ON UNLESS OTHERWISE SPECIFIED ALL DIMENSIONS ARE INCHES, AND BEFORE PLATING. ALL ANGLES ARE DEGREES TOLERANCES FRACTIONS DECIMALS ANGLES + + /64 + - -.005 deg - DRAWN DATE CHECKED APPROVED TITLE SIZE CODE IDENT NO COND REV
TYPICAL TWO VIEW DRAWING OF CYLINDRICAL OBJECT 6.250" 2.500".250" 3.375 DIA..750" DIA..000" DIA. NOTES:. MAT'L. = STAINLESS STEEL PER ASTM-A484 AND ASTM-A582 TYPE 303 2. UNLESS OTHERWISE SPECIFIED, HOLES, SLOTS, & DIAMETERS, SHALL BE PARALLEL AND CONCENTRIC WITHIN.003 T.I.R. 3. FINISH TO BE 63 UNLESS OTHERWISE SPECIFIED. 4. REMOVE BURRS AND BREAK SHARP CORNERS (.005 RAD. MAX.). USED ON UNLESS OTHERWISE SPECIFIED ALL DIMENSIONS ARE INCHES, AND BEFORE PLATING. ALL ANGLES ARE DEGREES TOLERANCES FRACTIONS DECIMALS ANGLES + + /64 + - -.005 deg - DRAWN DATE CHECKED APPROVED TITLE SIZE CODE IDENT NO COND REV
TYPICAL THREE VIEW DRAWING Top View ISOMETRIC VIEW Right Side View.000 Top View.500 2.000 Front View.500" Front View Right Side View ISOMETRIC VIEW ----------------------- ALL SQUARE & RECTANGULAR BLOCKS HAVE 6 SIDES. 2.000".000" NOTES:. MAT'L. = STAINLESS STEEL PER ASTM-A484 AND ASTM-A582 TYPE 303 2. UNLESS OTHERWISE SPECIFIED, HOLES, SLOTS, & DIAMETERS, SHALL BE PARALLEL AND CONCENTRIC WITHIN.003 T.I.R. 3. FINISH TO BE 63 UNLESS OTHERWISE SPECIFIED. 4. REMOVE BURRS AND BREAK SHARP CORNERS (.005 RAD. MAX.). USED ON UNLESS OTHERWISE SPECIFIED ALL DIMENSIONS ARE INCHES, AND BEFORE PLATING. ALL ANGLES ARE DEGREES TOLERANCES FRACTIONS DECIMALS ANGLES + + /64 + - -.005 deg - DRAWN DATE CHECKED APPROVED TITLE SIZE CODE IDENT NO COND REV
The Four Basic Line Types Common Tolerance Types Solid Line 2 /2" 2.500 [63.5] 2.500" 2.500 +/-.005 Hidden Line Centerline Phantom Line 2.500 +/-.005 [63.5] +/-.3 2.505 2.495 [63.62] [63.36] 2.505 2.495 Dimension Line Extension Line 2.500 +.00 -.002 Conversion Factor =.03937 =============== Metric to Inch = Factor x Dimension Inch to Metric = Dimension Div. by Factor UNLESS OTHERWISE SPECIFIED ALL DIMENSIONS ARE INCHES, AND BEFORE PLATING. ALL ANGLES ARE DEGREES TOLERANCES FRACTIONS DECIMALS ANGLES + + /64 + - -.005 deg - DRAWN DATE CHECKED TITLE USED ON APPROVED SIZE CODE IDENT NO COND REV
Blueprint Reading Calculating 'Max - Min - Mean' Dimensions 2.500 +.00 -.002 'B' (Basic Dimension) 'UT' (upper Tolerance) 'LT' ( Lower Tolerance) Legend B = Basic Dimension UT = Upper Tolerance LT = Lower Tolerance Mean = Mean Dimension Max = B + UT Min = B - LT Mean = (Max + Min) / 2 Example 2.500 +.00 -.002 Max = B + UT Min = B - LT = 2.500 +.00 = 2.500 -.002 Max = 2.50 Min = 2.498 Mean = (Max + Min) /2 = (2.50 + 2.498) /2) = 5.008 /2 Mean = 2.504
+/- /64
Class Assignment Converting Metric To Inch (0 Dimensions) Calculating Max Mean } Dimensions Min
Test Converting Metric To Inch Calculating Max Mean } Dimensions Min 5.2 +/-.02 2.05 +/-.0 3 6.9 +/-.25 4.98 +/-.25 0.43 +/-.0
Threads Parts of a Screw Thread Crest Included Angle Minor Diameter Pitch Diameter Major Diameter Root Pitch Single Depth
THE TYPICAL THREAD DESIGNATION The English Format UNIFIED NATIONAL THREAD FORM NUMBER OF THREADS PER INCH MAJOR DIAMETER THREAD SERIES C = COURSE F = FINE CLASS OF FIT # = LOOSE #2 = MEDIUM #3 = TIGHT /2-3 UNC - 2B B = INTERNAL A = EXTERNAL The Metric Format MAJOR DIAMETER (In Millimeters) INDICATES A METRIC THREAD THREAD PITCH (In Millimeters) PITCH DIA. SPECIFICATION MAJOR DIA. SPECIFICATION M0 x.25-5g 6g TOLERANCE GRADE TOLERANCE POSITION TOLERANCE GRADE TOLERANCE POSITION Lower Case = External Upperr Case = Internal CLASS OF FIT EXTERNAL INTERNAL ------------------------------------------ FINE 4h 5H medium 6g 6H course 8g 7H e = Large Allowance g = Small Allowance h = No Allowance G = Small Allowance H = No Allowance
THE TYPICAL THREAD DESIGNATION Metric/Inch Comparison (Course Threads) No Course/Fine Thread Distinction (Metric Only) Thread Pitch In Millimeters Thread O.D. In Millimeters ISO Thread Symbol.8.0984.0984.0984.0787.0787.0688.0590.0492.0393.0393.0393.034.0295.0275.0236.096.077.077.057.037.037 M24 x 3 M22 x 2.5 M20 x 2.5 M8 x 2.5 M6 x 2.0 M4 x 2.0 M2 x.75 M0 x.5 M8 x.25 M7 x.0 M6.3 x.0 M6.0 x.0 M5 x 0.80 M4.5 x 0.75 M4 x 0.70 M3.5 x 0.60 M3 x 0.50 M2.5 x 0.45 M2.2 x 0.45 M2 x 0.40 M.8 x 0.35 M.6 x 0.35.945.866.787.7086.630.55.472.394.35.2755.248.2362.97.77.57.38.8.0984.0866 Thread O.D. Inch Equivalent.26.90.64.38.25.2.099.086.079.07.073.063 Thread Pitch Inch Equivalent - 8 7/8-9 3/4-0 5/8-9/6-2 /2-3 7/6-4 3/8-6 5/6-8 /4-20 2-24 0-24 8-32 6-32 5-40 4-40 3-48 2-56 - 64 Thread O.D. In Inches Threads Per Inch.250..000.0909.0833.0769.074.0625.0555.0500.046.046.032.032.0250.0250.0208.078.056
THE TYPICAL THREAD DESIGNATION Metric/Inch Comparison (Fine Threads) No Course/Fine Thread Distinction (Metric Only) Thread Pitch In Millimeters Thread O.D. In Millimeters ISO Thread Symbol.0787.059.059.059.059.059.0492.0492.0393.0393.0393.0393.034.0295.0275.0236.096.077.077.057.037.037 M24 x 2 M22 x.5 M20 x.5 M8 x.5 M6 x.5 M4 x.5 M2 x.25 M0 x.25 M8 x.0 M7 x.0 M6.3 x.0 M6.0 x.0 M5 x 0.80 M4.5 x 0.75 M4 x 0.70 M3.5 x 0.60 M3 x 0.50 M2.5 x 0.45 M2.2 x 0.45 M2 x 0.40 M.8 x 0.35 M.6 x 0.35.945.866.787.7086.630.55.472.394.35.2755.248.2362.97.77.57.38.8.0984.0866 Thread O.D. Inch Equivalent.26.90.64.38.25.2.099.086.079.07.073.063 Thread Pitch Inch Equivalent - 2 7/8-4 3/4-6 5/8-8 9/6-8 /2-20 7/6-20 3/8-24 5/6-24 /4-28 2-28 0-32 8-36 6-40 5-44 4-48 3-58 2-64 - 72 Thread O.D. In Inches Threads Per Inch.0833.074.0625.0555.0555.050.050.046.046.0357.0357.032.0277.025.0227.0208.072.056.038
Slyles of Thread Representation The Following are Three Methods of External Thread Representation The Following Drawings show Three different methods of Representing Internal Threads, Both Through hole Threads and Blind, Bottom Threaded Holes.
DECIMAL EQUIVALENTS & TAP DRILL SIZES FRACTION OR DRILL SIZE DECIMAL EQUIVALENT TAP SIZE FRACTION OR DRILL SIZE DECIMAL EQUIVALENT TAP SIZE FRACTION OR DRILL SIZE DECIMAL EQUIVALENT TAP SIZE 5/6 ---------------------.325 3/8-6 O.360 P.3230 2/64 ---------------------.328 Q.3320 3/8-24 5/8 -----.6250 4/64 ------------------------.6406 2/32 -----------------------.6562 3/4-0 43/64 -----------------------.679 /6 -----.6875 3/4-6
Using The Decimal Equivalent Chart Students Name. Please give the correct Decimal Equivalent for the following fractions. /4 = 27/64 = 5/32 = /64 = 3/6 = /2" = 9/6 = 7/32 = 3/32 = 2. Please give the correct Diameter of the following Drills. Z # #60 U #2 Q F 9/32 27/64 7/64 #80 " 3. Please write the correct Drill that corresponds with the following Decimal Equivalents..42.56.43.368.09.234.32.875.332.377.28.062
THREAD QUIZ # A TYPICAL THREAD DESIGNATION ****** 7/8-4 UNC - 2B ******. The above Thread Designation indicates how many threads per inch? 2. The above Thread Designation indicates what Form of Thread? 3. The above thread designation indicates what Series of thread? 4. What is the Major Diameter of the above thread? 5. In the above thread, what does the 'B' Indicate? 6. What does the number '2' indicate in the above thread? 7. Name the three common drill sets found in most Machine Shops. 8. Give the decimal equivalents for the following fractions. 3/8 5/32 2/32 5/6 /6 3/64 /64 57/64 7/32 " 2/64 Pleas write the correct diameter of the following Twist Drills. P K #4 #2 F U #60 #38 #55 #
Flanged Sleeve (BP - 8B) Student Name. What is the name of the part?. 2. What is the order number? 2. 3. How many pieces are required? 3. 4. What material will be used? 4. 5. Name the two views which are used to represent the Flanged Sleeve. 5. 6. Name the kind of line indicated by each of the following encircled letters. 6. A A B C D E F G B C D E F G 7. What is the outside diameter of both flanges? 7. 8. What is the height (Thickness) of each flange? 8. 9. What is the diameter of the center hole? 9. 0. Does the hole go all the way through the center of the sleeve? 0.. What is the diameter of the hidden circle A?. 2. Determine the total or overall height of the Flanged Sleeve. 2.
Class Exercise #4 2.000 Dia..998.000 Dia..998.500 Dia. Ream A.750 B C X 2.375 2.750 4.875 D 3/4 Z.750 Dia. +.002 -.000 E 2 7/8 Dia..250 Dia. +.002 -.000 Name -- Lower Drum Shaft Material -- Aluminum Drawn By -- R.M. Quantity -- 4 Date -- 9/30/96 Print # -- 655g Tolerances -- Decimals +/-.005 -- Fractional +/- /64 -- Angular +/- /2deg. Lower Drum Shaft
Class Exercise #4 Questions Students Name Lower Drum Shaft -----------------------. What is the name of the part? 2. What Material will the part be made from? 3. What is the Print number? 4. What is the basic shape of the part? 5. What is the overall length? 6. What is the largest Diameter? 7. How many Internal and External diameters does the part have? 8. What is the diameter of the smallest hole? 9. What is the diameter of the largest hole? 0. To what Depth is the larger hole bored into the Part?. What is the length of the reamed hole? 2. What is the length of dimension 'X'? 3. What is the Length of the section that is.000 Dia.? 4. What is the correct value for dimension 'Z'? 5. What is the length of the part from face 'A' to shoulder 'C'? 6. What is the length of the part from face 'E' to shoulder 'C'? 7. What amount of Tolerance is permitted on fractional dimensions where tolerance is not specified? ' 8. What amount of tolerance is permitted on decimal dimensions where tolerance is not specified? 9. How many diameters are being held within limits of accuracy smaller than +/-.005"?
Basic Print Calculations Slove For The Following Dimensions. A = 4. D = 2. B = 5. E = D 3. C = 6. F =.720 dia. A 0.445".40" 0.694".074" B.680 2.254".406 E.948 F C.293" X.B --.20 DIA. C --.562 DIA. D --.280 DIA. A --.523 DIA. E --.375 DIA. Please calculate the center distance between; Center Distance A -- B =.624".22".646" 2.57" Center Distance B -- D = Center Distance C -- E = Center Distance A -- E = Center Distance C -- D = Distance 'X' = 2.880" 3.329"
Class Exercise #5 B E G Y 9/32 dia. 4 Holes ~Equally Spaced F Z 2 7/8.25 +.002 -.000 Bore 5/8 C 2.250 Dia. Bolt Hole Circle D X.625 A 2 /8 6 Required -- Mat'l. = Cast Iron -- Scale = :- UNLESS OTHERWISE SPECIFIED ALL DIMENSIONS ARE INCHES, AND BEFORE PLATING. ALL ANGLES ARE DEGREES TOLERANCES FRACTIONS DECIMALS ANGLES + + /64 + - -.005 deg - DRAWN DATE CHECKED TITLE Flanged Bushing USED ON APPROVED SIZE CODE IDENT NOCOND REV
Class Exercise #5 Questions Student Name Flanged Bushing -----------------------. How Many drill holes are required? 2. What drill size is required for these holes? 3. What diameter Bolt Hole Circle are the four 9/32 dia. holes on? 4. What type of line is line 'A'? 5. What type of line is line 'E'? 6. What lines in the front view are the projections for diameter 'D' in the right side view? 7. What kind of lines are indicated by letters 'B' and 'C'? 8. What line in the front view represents surface 'F'? 9. What is the overall length of the Bushing? 0. What is the minimum diameter permitted for hole 'D'?. What is the maximum diameter hole 'D' can be bored? 2. What is the 'mean' diameter for hole 'D'? 3. What is the tolerance allowed on 'unspecified' decimal dimensions? 4. What is the outside diameter of the flange? 5. What is the correct value for Flange thickness 'X'? 6. What is the Body length of the Bushing? 7. What is the maximum measurement allowed for the Body length? 8. What is the outside diameter of the Body? 9. What is the wall thickness of the main body? 20. What is the correct value for distance 'Y'? 2. What is the correct value for distance 'Z'? 22. What is the Max and Min angular dimension allowed
MICRO FINISHES Relation of Surface Roughness to Dimensional Tolerances There is a distinct relationship between the permissable surface roughness of the part and dimensional tolerance. The measurement of surface roughness involves the determination of the average linear deviation of the actual surface from the nominal surface. Therefore, the requirement for the required measurement of a dimension is that the variation introduced by surface roughness should not exceed the dimensional tolerance. If this is not the case, the measurement of the dimension will be subject to a variation greater than the required tolerance. When the average roughness height of a surface exceeds /8 the dimensional tolerance, the entire tolerance could be taken up by the roughness height. The following finish symbols show the surface roughness allowed within a given dimensional tolerance. Symbol Maximum Surface Roughness Total Dimensional Equivalent Machining Allowed By Tolerance Micrometer( ) Process Dimensional Tolerance Linear Inches Microinch ( ) 8 8.000".20 Lapping.000 008.000 000 2 6 6.0002".40 Honing/Grinding.000 06.000 000 4 32 32.0003".80 Fine Boring/Turning.000 032.000 000 8 Grinding Med.Boring/Turning 63 63.0006".6 Reaming - Milling.000 063.000 00 6 Broaching 25 25.00" 3.2 Finish End Milling.000 25.000 003 2 Finish Side Milling 250 250.002" 6.3 End Milling.000 250.000 006 3 Side Milling 500 500.004" 2.5 Rough Milling.000 500.000 02 5 Rough Turning 000 000.008" 25 Flame/ Torch Cutting.00 000.000 025 Misc. Notes Lay Symbols ANSI = American National Standards Institute = Any manufacturing process = Perpendicular M = Multi-directional = Maching process required I I = Parallel C = Circular G R L = Grind = Ream = Lap X = Angular R = Radial = Non-Maching process