IN-DIE TAPPING TOOLS TECHNICAL INFORMATION MANUAL

Transcription

1 IN-DIE TAPPING TOOLS TECHNICAL INFORMATION MANUAL CALL TOLL FREE: FAX: Danly IEM, A Division of Connell Limited Partnership

2 THIS MANUAL CONTAINS INFORMATION APPLICABLE TO THE FOLLOWING IN-DIE TAPPING TOOL MODELS: HY1024 ME1024 LP25M6 (Patent # ) TABLE OF CONTENTS PAGE NUMBER PRODUCT SPECIFICATIONS 2 ACCESSORIES 5 TAPPING DEPTH/MATERIAL THICKNESS CHARTS 8 FORMING TAP PRE-HOLE SIZE CHARTS 9 APPLICATION DRAWINGS 11 DESIGNING A CAM DRIVER 38 RAPID T.A.P. CAM DESIGN SOFTWARE INTRODUCTION 39 TROUBLE SHOOTING 40 1

3 HY1024 Series for Hydraulic Presses HY1024 Product Features The HY is the smallest and most compact of the tapping tools. The HY1024 is an economical solution for tapping from the top down in a hydraulic press. Since the HY1024 is not cam actuated, the press controls the acceleration and tap speed. The HY1024 will tap size #0 - #12 or up to M5 and typically runs at production rates between strokes per minute up to a maximum 200 (SPM) rate based on strip material, tap size and tap pitch. By utilizing multiple tools in place of one special tapping tool, you can control flexibility in the stamping operation and greatly reduce downtime due to unscheduled maintenance. NOTES: The HY1024 tapping tool cannot be used in a mechanical press. See the ME1024 or the LP25M6 for applications requiring use in a mechanical press. HY1024 footprint dimensions Notes: Tapping depth/maximum material thickness can be found on Page 8. Metric dimensions are in italics. 2

4 ME1024 Series for Mechanical Presses Product Features The ME1024 is a simple and compact tool with a small footprint for tapping top down in a mechanical or hydraulic press. The ME1024 utilizes a cam driver to control tool acceleration. The ME will tap size #0 - #12 or up to M5 and typically runs at production rates between strokes per minute up to a maximum of 200 (SPM) based on strip material, tap size and pitch. The cam driver is designed as a separate functional piece to maximize die design flexibility and take the sinusoidal motion that is inherent with mechanical presses and turn it into a rotary tapping motion. The cam driver mounts easily on a punch plate or upper die shoe above the tapping tool. The cam driver is application specific and can be manufactured by using the free Rapid TAP CAD design software. By utilizing multiple tools in place of one special tapping tool, you can control flexibility in the stamping operation and greatly reduce downtime due to unscheduled maintenance. ME1024 A = TAPPING STROKE ME1024 footprint dimensions Notes: Tapping depth/maximum material thickness can be found on Page 8. All dimensions are in inches. 3

5 LP25M6 & LP516M8 Series for Mechanical Presses LP25M6 Product Features The LP is the most versatile tool with a simple and compact design for tapping top down, bottom up or at any angle. The LP utilizes a cam driver to control tool acceleration and tap speeds. The LP25M6 will tap size #0-1/4 or M6 and the LP516M8 will tap 1/4" - 5/16" or M8 while making either right or left-hand threads. The LP typically runs at production rates between strokes per minute up to a maximum of 100 (SPM) based on strip material, tap size and pitch. The cam driver is designed as a separate functional piece to maximize die design flexibility and take the sinusoidal motion that is inherent with mechanical presses and turn it into a rotary tapping motion. The cam driver mounts easily on a punch plate on the upper die shoe above the tapping unit to provide the proper amount of tap acceleration and a positive return. The cam driver is application-specific and can be manufactured by using the free Rapid TAP CAD design software. By utilizing multiple tools in place of one special tapping tool, you can control flexibility in the stamping operation and greatly reduce downtime due to unscheduled maintenance. LP Cam Driver profile Important Note The shut height from the bottom of the upper shoe to the mounting surface of the unit cannot be less than 3.775", unless modified (see installation manual). LP25M6 & LP516M8 footprint dimensions NOTE A: Dowel pin holes ±0.001 Fastener holes ±0.005 Notes: Footprint dimensions are identical for both units. However, performance variations exist between the two units. Consult the Rapid Tap software. Tapping depth/maximum material thickness can be found on Page 8. All dimensions are in inches. 4

6 LP Extensions Accessories and Replacement Parts Some applications require a wide strip width incorporating a tapped hole located a distance from the edge of the material. The LP integrates modular extensions in combination with a standard tool to provide flexibility in design and off-the-shelf type components. The standard Cam Extension provides over 9" of extra length while the extra long extension provides over 19". All components are made from the best materials for maximum life and performance. LP STANDARD EXTENSION LP EXTRA LONG EXTENSION Notes: All dimensions are in inches. 5

7 Taps are sold in packs of 12. Accessories and Replacement Parts Forming Taps Product Features The special forming taps used in the in-die taping units are available in inch and metric standard sizes listed below. All forming taps are sold with a TiN coating as standard. Other coatings for special material applications are available on request. Forming taps provide a superior quality and finish of thread, with no chip formation. INCH SIZES Part Number Shank Size 1 Tap Size & D Limit R Small RH3 R Small RH5 R Small RH7 R Small RH5 R Small RH5 R Small RH5 R Small RH5 R Small RH7 R Small RH5 R Small RH7 R Small RH6 R Small RH8 R Small RH6 R Small RH6 R Small RH6 R Medium 1/ RH6 R Large 1/ RH6 R Medium 1/ RH6 R Large 1/ RH6 R Large 5/16-32 RH6 R Large 5/16-24 RH6 R Large 5/16-18 RH7 METRIC SIZES Part Number Shank Size 1 Tap Size & D Limit R Small M2.0 x.40 D5 R Small M2.5 x.45 D5 R Small M3.0 x.50 D5 R Small M3.5 x.60 D6 R Small M4.0 x.70 D6 R Small M5.0 x.80 D7 R Medium M6.0 x 1.00 D8 R Large M6.0 x 1.00 D8 R Large M8.0 x 1.00 D8 R Large M8.0 x 1.25 D8 Standard Stock Taps are TiN Coated Special Tap Sizes, Pitches and Coatings are Available per Quotation 1 Tap diameter shank size application: Small 0 - #12 (M2 M5) diameter taps: use in HY1024, ME1024, LP25M6 Medium ¼" (M6) diameter taps: use in LP25M6 Large ¼" 5/16 (M6 - M8) diameter taps: use in LP516M8 6

8 Accessories and Replacement Parts Pitch Inserts/Tap Holders Product Features Pitch inserts are interchangeable components of the tapping operation and are specific to the tap pitch of the tapped hole. Each pitch insert contains a tap holder with a quick release depression collar. Taps can easily be changed within seconds in most applications. For applications needing a little extra reach to tap inside an embossment, a pitch insert extension can be made specific to your needs. Our engineering department will work with you on your specific application. INCH SIZES Tap Part Part Part Holder Number Number Number Pitch Size 1 for for for HY/ME1024 LP25ME LP516M8 56 Small R R Small R R Small R R Small R R Small R R Medium R Large R Small R R Large R Medium R Large R Large R METRIC SIZES Tap Part Part Part Holder Number Number Number Pitch Size 1 for for for HY/ME1024 LP25ME LP516M mm Small R R mm Small R R mm Small R R mm Small R R mm Small R R mm Small R R mm Medium R mm Large R mm Large R Pitch insert for non-standard sizes or pitches are by quotation. 1 Tap diameter shank size application: Small 0 - #12 (M2 M5) diameter taps: use in HY1024, ME1024, LP25M6 Medium ¼" (M6) diameter taps: use in LP25M6 Large ¼" 5/16" (M6 - M8) diameter taps: use in LP516M8 7

9 Maximum Tapping Depth/ Material Thickness MAXIMUM MATERIAL THICKNESS (T) - INCH Size and HY & ME Pitch 1024 LP25M6 LP516M / / /16x32UN /16x24UN /16x18UN MAXIMUM MATERIAL THICKNESS (T) - METRIC Size and HY & ME Pitch 1024 LP25M6 LP516M8 M2 x M2.5 x M3 x M3 x M3.5 x M4 x M5 x M5 x M6 x M8 x M8 x NOTE: Maximum material thickness (T) includes extrusion height and.020 inch (or 0.5mm) gap between the tip of the tap and the top of the material stock. 8

10 Pre-Hole Sizes METRIC COLDFORMING TAPS 65% THREAD 70% THREAD 75% THREAD TAP SIZE/ THEOR. HOLE THEOR. HOLE THEOR. HOLE PITCH (mm) SIZE (mm) SIZE (mm) SIZE (mm) M3 x M3 x M3.5 x M4 x M4 x M4.5 x M5 x M5 x M6 x M6.3 x M7 x M8 x M8 x M10 x M10 x M12 x M12 x NOTE: The shaded pre-hole sizes in the above table have been changed, as they were incorrectly calculated in earlier versions of this manual. PRE-HOLE SIZE CALCULATION Hole size = Basic Major Diameter - Percent of Full Thread x mm Pitch Example: Find the theoretical pre-hole punch size for M8 x 1.25mm to produce 65% thread: Hole size = x 1.25 / = = 7.448mm NOTE: Tapping an undersize hole may result in tap breakage due to excessive torque. As a starting recommendation, 65% thread should be considered. Tapping over 75% of thread is not recommended. 9

11 Pre-Hole Sizes INCH COLDFORMING TAPS 65% THREAD 70% THREAD 75% THREAD TAP SIZE/ THEOR. HOLE THEOR. HOLE THEOR. HOLE PITCH (in) SIZE (in) SIZE (in) SIZE (in) 0 80 NC NC NF NC NF NC NF NC NF NC NF NC NF NC NF NC NF NC NF /4 20 NC /4 28 NF /16 18 NC /16 24 NF /8 16 NC /8 24 NF /16 14 NC /16 20 NF /2 13 NC /2 20 NF PRE-HOLE SIZE CALCULATION Hole size = Basic Major Diameter - Percent of Full Thread Number of Threads per Inch Example: Find the theoretical pre-hole punch size for 1/4-20 to produce 65% thread: Hole size = x 65/20 = = inches NOTE: Tapping an undersize hole may result in tap breakage due to excessive torque. As a starting recommendation, 65% thread should be considered. Tapping over 75% of thread is not recommended. 10

12 FIGURE #1 LOW PROFILE TOOLS TAPPING FROM THE BOTTOM UP THIS DRAWING IS SHOWING THE LP25M6 IN THE CLOSED POSITION. NITROGEN SPRING CAN BE USED TO ELIMINATE TOO LONG OF A DIE SPRING. SPRING TRAVEL IS BASED ON TAPPING STROKE, PLUS PRELOAD ON MATERIAL BEFORE TAPPING. (PRELOAD WILL INSURE PROPER STRIPPING FOR TAPPING.) CUSTOMER CAN USE A BRIDGE STRIPPER INSTEAD OF A SPRING STRIPPER IF DESIRED. MATERIAL UPPER DIE MATERIAL SPACER BLOCK (IF NEEDED) STRIPPER DIE DIE 1/4 S.H.C.S. 8 PLACES CAM BOTTOM DIE MACHINED POCKETS FOR CAM CLEARANCE MACHINE POCKET IN DIE SET FOR DESIRE HEIGHT. HEEL BLOCK MACHINE GROOVE TO ALLOW PASSAGE FOR GREASE GUN. D

13 FIGURE #2 LOW PROFILE TOOLS TAPPING FROM THE TOP DOWN LP25M6 IS BOLTED TO THE STRIPPER AND THE SUPPORT BLOCK REMOVE BRIDGE PLATE, (1.00 inch THICK) THIS WILL ALLOW A SMALLER SHUT HEIGHT. S.H.C.S. TO HOLD CAM TO DIE. UPPER DIE HEEL BLOCK CAM CAM DIE STRIPPER BOTTOM DIE BOLT MACHINED POCKETS FOR CAM CLEARANCE SUPPORT BLOCK D

14 FIGURE #3 HEEL BLOCKS FOR LOW PROFILE TOOLS FRONT HEEL BLOCK BACK HEEL BLOCK.125 RAD (2PLS) DRILL TAP (3 PLS) DRILL C-BORE FOR SHCS (3 PLS) DRILL TAP 6-32 (3PLS).25 RAD (2PLS) 45 X.02 (4PLS) CLEARANCE POCKETS FOR CAM FRONT HEEL BLOCK BACK HEEL BLOCK DRILL C-BORE FOR 6-32 SHCS (3PLS) CAM TRACK CAM FOLLOWER X.02 (4PLS) PARALLEL SHIMS FOR CLEARANCE ON SET UP D

15 FIGURE #4 POSITION FOR CAM FOLLOWERS (RIGHT-HAND THREADING ONLY) POSITON A POLYGON DRIVE SHAFT. D

16 FIGURE #5 LP25M6 & LP516M8 CAM DRIVER MOUNTING INFORMATION DRILL AND C-BORE FOR 1/2-13 SHCS (4PLS).500 DOWEL PIN (2PLS) CAUTION BOLTS AND DOWEL PINS CAN`T MOUNT BELOW THIS SURFACE. D

17 FIGURE #6 LOW PROFILE TOOLS MOUNTED ON A STRIPPER PLATE BRIDGE STRIPPER HEEL BLOCK HEEL BLOCK BOSS TIP OF TAP SHOULD NOT EXTEND BELOW BOSS. BOSS SHOULD NOT EXTEND BELOW STRIPPER PLATE. D

18 FIGURE #7 RECOMMENDED LUBRICATION SYSTEM OPTION #1 STRIPPER PLATE NOZZLE SHOULD BE WITHIN.02 TO.100 OF THE DIA OF TAP. MACHINE SLOT OR DRILL POCKET FOR TUBE. SLOT IS PROVIDED IN PITCH INSERT TO ALLOW 3/32 BRASS TUBING TO PASS THRU. 3/32 OD X.06 ID BRASS TUBING.093 ID X 1/8 OD TEFZEL TUBING USE TUBING THAT WILL WITHSTAND 1,1,1 TRICHLORETHANE. THIS COMPOUND IS USED IN GOOD TAPPING FLUIDS. D

19 FIGURE #8 RECOMMENDED LUBRICATION SYSTEM OPTION #2 STRIPPER PLATE NOZZLE SHOULD BE WITHIN.02 TO.100 OF THE DIA OF TAP. 3/32 OD X.06 ID BRASS TUBING MACHINE SLOT OR DRILL POCKET FOR TUBE. SLOT IS PROVIDED IN PITCH INSERT TO ALLOW 3/32 BRASS TUBING TO PASS THRU. 1/8 OD X.097 ID BRASS TUBING EITHER USE SOLDER OR E-POXY (JB WELD) IF TUBE NEEDS TO BE BENT, USE A TUBE BENDER COMPRESSION FITTING FOR 1/8 DIA TUBE 1/8 MALE PIPE THREAD IS 5090K11 1/8 FEMALE PIPE THREAD IS 5089K11 D

20 FIGURE #9 PITCH INSERT ASSEMBLY BOSS OR STRIPPER COLLET TAP FEMALE LEAD SCREW MALE LEAD SCREW KEY STOCK MIS-FEED SPRING D

21 FIGURE #10 SHUT HEIGHT OF CLEARANCE AT THE END OF THE STROKE MIMIMUM SHUT HEIGHT CLEARANCE HOLES WILL BE REQUIRED IN DIE SHOE FOR CAM SIDE PLATES. D

22 FIGURE #11 FIXED CAM DIMENSIONS FOR THE LP CAM DRIVER (RAPID TAP SOFTWARE WILL SELECT EITHER CAM A OR CAM B).005 ABC C B ENGRAVE JOB NUMBER PLS A.375 2PLS CAM A /8 PRESS FIT DOWEL PIN 4 PLS TAP AND C-BORE FOR 5/16-18 X 1.00 S.H.C.S 4 PLS PLS PLS CAM B /8 PRESS FIT DOWEL PIN 4 PLS TAP AND C-BORE FOR 5/16-18 X 1.00 S.H.C.S 4 PLS CAM TRACK HEIGHT CAM TRACK HEIGHT.50 OF STRAIGHT.50 OF STRAIGHT CAUTION BOLTS CAN`T MOUNT BELOW THIS SURFACE MINIMUM DIM BREAK ALL SHARP EDGES FINISH: NONE MATERIAL: 7075-T6 ALUMINUM MATERIAL CAM BE REMOVED TO ADD CLEARANCE..500 MIN DIM FROM END OF CAM TRACK TO EDGE OF MATERIAL. D

23 FIGURE #12 LOW PROFILE TOOLS MOUNTED ON A SPRING STRIPPER SPRING TRAVEL IS BASED ON TAPPING STROKE, PLUS.25 OF PRELOAD. 4 NITROGEN SPRINGS EQUALLING 3000 LB BEFORE CAMS MAKE CONTACT WITH CAM FOLLOWERS..500 DIA LOCATING PINS (4PLS) THIS WILL KEEP THE STRIPPER PLATE FROM SHIFTING WHEN THE CAMS MAKE CONTACT WITH THE CAM FOLLOWERS. D

24 FIGURE #13 TAPPED HOLE DETECTION (TO DETERMINE WHETHER THE TAP FULLY PENETRATES THROUGHT THE MATERIAL) MATERIAL GUIDES DIE SPRING DIE PLATE SPRING SET SCREW WITH THRU HOLE SWITCH SPRING LOADED BRIDGE STRIPPER MATERIAL STRIP GUIDE PINS CLEARANCE BETWEEN MATERIAL AND PLUNGER IS 2.5 X PITCH D

25 FIGURE #14 EXAMPLE OF 13 LP TAPPING UNITS TAPPING FROM THE BOTTOM UP D

26 FIGURE #15 EXAMPLE OF LP25M6 TAPPING UP AND DOWN IN THE SAME STATION D

27 FIGURE #16 CAM DRIVER TEMPLATE FOR ME1024 CAM TEMPLATE FOR ME OIL HOLE.375 RAD (4 PLS) (2 PLS).250 (2 PLS) GREASE FITTING (45 DEG ANGLE) (2 PLS) DIA NOTE: MIN SHADED AREA TO BE MACHINED BY CUSTOMER BASED ON APPLICATION 1 CAM PROFILE DETERMINED BY PRESS STROKE AND TAPPING STROKE MODEL ME STANDARD CAM OPEN AND SHUT HIEGHTS D

28 FIGURE #17 ME1024 CAM FIXED DIMENSIONS ENGRAVE JOB NUMBER RAD (2 pls).375 RAD (4 PLS) R (4pls) (2 pls).250 (2 pls) (2 pls) DIA FINISH: NONE MATERIAL: 7075-T6 ALUMINIUM D

29 FIGURE #18 ME1024 CAM ON BRIDGE STRIPPER.630 CLEARANCE HOLE FOR DRIVE SCREW MATERIAL GUIDES DIE SPRING DIE PLATE SPRING LOADED BRIDGE STRIPPER MATERIAL STRIP GUIDE PINS D

30 FIGURE #19 CAM DRIVER MOUNTING FOR ME1024 CAM USING A SPRING STRIPPER THIS SECTION IS REMOVED BY END USER BASED ON PROPER HEIGHT REQUIREMENTS THIS DIM. IS THE SAME FOR ALL CAM`S, WHEN USED IN A SPRING STRIPPER APPLICATION. SUBTRACT AMOUNT OF PRELOAD TRAVEL USED BEFORE TAPPING FROM THIS 1.00 DIM. IN MOST CASES USE.05 TO.100 OF PRELOAD TRAVEL. THIS WILL INSURE PROPER STRIPPING FOR TAPPING. SPRING TRAVEL IS BASE ON TAPPING STROKE, PLUS PRELOAD ON MATERIAL BEFORE TAPPING. MATERIAL DIE MICRO SWITCH CAUTION IF USING A SPRING STRIPPER. THERE SHOULD BE A SENSOR TO MAKE CERTAIN THAT THE STRIPPER COMES DOWN 100%. IF STRIPPER DOES NOT COME DOWN ALL THE WAY THE UNIT COULD BOTTOM OUT, CAUSING THE CAM ROLLER TO BREAK. D

31 FIGURE #20 MOUNTING THE ME1024 UNIT IN A HYDRAULIC PRESS OPEN.625 DIA X 1.35 DEEP RELIEF HOLE IN PUSH BLOCK FOR SCREW MINIMUM THIS KEEPS PUSHER BLOCK FROM MAKING CONTACT ON CAM PLATES. CAM PLATE CLOSED D

32 FIGURE #21 TAPPING WITH MATERIAL LIFTERS STOP BLOCK TO OVER COME NITROGEN SPRINGS SPRING BRIDGE STRIPPER.50 DIA SPRINGS MATERIAL TRAVEL NITROGEN SPRINGS MATERIAL LIFTERS SUPPORT PAD APPROXIMATELY 1800 LB OF NITROGEN PRESSURE. D

33 FIGURE #22 SAMPLE LAYOUT FOR MULTIPLE TAPPING WITH 3 ME1024 UNITS IN ONE DIE ME1024 TAPPING UNITS AIR CLAMP AIR FEEDER NOTE: ALL DIMENSIONS ARE APPROXIMATE D

34 FIGURE #23 TYPICAL WAY OF APPLYING TAPPING UNITS TO IN-DIE TAPPING MOUNTING SCREWS FOR CAM FIRST HOLE TAPPED PART PUNCHED OUT PUNCH HOLES FOR TAPPING SECOND HOLE TAPPED THIRD HOLE TAPPED THIS DIE HAS ONE MACHINED POCKET FOR ALL TAPPING UNITS TAPPING UNITS 1,2,3 3/8-16 S.H.C.S PART THREE HOLES TAPPED MACHINED POCKET THIS DIM. IS FROM THE TOP OF THE MATERIAL OR EXTRUSION TO THE TOP OF THE CAM IN THE CLOSED POSITION 2.00 DIE MATERIAL 3.00 BOTTOM DIE SET 5.00 PARALLEL 1.00 D

35 FIGURE #24 SUB-PLATE FOR LP25M6 GUIDE RAIL 1/4-20 1/2-20 GUIDE RAIL STOP BLOCK SUB-PLATE D

36 FIGURE #25 SUB-PLATE FOR LP25M6 CAM SUB-PLATE 5/16-18 S.H.C.S. RAIL STOP BLOCK D

37 FIGURE #26 SUGGESTED LAYOUT FOR TAPPING BOTTOM UP WITH LOW PROFILE TOOLS AND USING A SUB DIE DIE IN OPEN POSITION DIE IN CLOSED POSITION D

38 FIGURE #27 LP25M6 MOUNTED ON A SPRING STRIPPER MATERIAL LIFTER STOP BLOCKS OR NITROGEN SPRINGS TO OVER RIDE 3,000 LBS OF SPRING PRESSURE. FORMING TRAVEL APPROXIMATIELY 3,000 LBS OF SPRING PRESSURE. D

39 Designing a Cam Driver (Models ME1024 and LP25M6 only) 1. TOOL MODEL: ME1024 LP25M6 2. STROKE OF PRESS: 3. TAPPING STROKE: The remaining stroke left after the material has advanced in its progression. Example: If a 6" stroke press requires 2" to advance or progress, the tapping stroke would be (6" - 2") = 4". 4. SPEED OF PRESS IN STROKES PER MINUTE: 5. TOTAL THICKNESS OF MATERIAL (include extrusion if applicable): Material thickness must include the gap between the tip of the tap and the top of material or extrusion. (Failure to do so could cause improper tap penetration.) (See Figure #15.) 6. MATERIAL TYPE: 7. TAP SIZE: 38

40 Rapid T.A.P. Software Rapid T.A.P. Software (Tapping Application Program) Software that aids in the development of dies with Danly IEM in-die-tapping tools. This software is designed to educate die designers and stamping facilities on the benefits of In-die Tapping (IDT) and provide easy ways to design dies that incorporate the IDT tools. Rapid TAP replaces Campro, an earlier DOS based computer program. Rapid TAP produces needed CAD information for the IDT Cam Drivers that are proprietary to Danly IEM tapping tools. Rapid TAP s program logic evaluates the sinusoidal acceleration that is inherent with mechanical presses and converts it into a linear tapping motion. This conversion is more accurate than altering gear ratios 39

41 Trouble Shooting 1. DISTORTED THREADS Threads are distorted and the go-gage will not go into the tapped hole. Check to see if any portion of the die is hitting the top of the threads, such as the stripper plate, form block or a hold-down form pad. If this is the case, provide clearance for the hole by grinding or machining a counter bore. 2. TAP BREAKS ON EVERY HIT Make sure the hole is the correct size for a metal forming tap. If you are using a hole size recommended for a cutting tap, it is too small and will result in tap breakage. Ensure that the hole is being registered properly beneath the tap. See Mounting Procedures in the installation manuals. For recommended pre-hole sizes, refer to the tables on pages 9 and 10 of this manual. 3. TAP BREAKS AFTER ONE TO FIVE HITS Tap height may be misadjusted and stocking out below the nose piece or boss. This condition often results in the tap catching on the material as at advances. 4. TAP BREAKS PREMATURELY Check the lubrication. A discolored or black tap indicates that an improper level nor type of lubrication is being applied. 5. TAP SPINS BUT DOES NOT PENETRATE THE HOLE The tap is backed up by a spring for no hole conditions. If this spring is weak there may not be enough pressure to get the tap started. If a spring stripper or a spring loaded bridge stripper is used, adjust the tap so that is protrudes slightly from the nose piece. This will put a preload on the spring and increase spring pressure. If this does not correct the condition, a stronger spring will have to be used. Call the factory for assistance if this is the case. 6. IF CHIPS ARE DEVELOPING The pre-hole for the tap is too small. Opening up the hole by.002" to.003" will usually fix the problem. Use 65% of thread to start with. 40