D10B-18 REVISED MARCH, 2016 © Copyright 2023. All rights reserved. No portion may be copied or reproduced in any manner. TOOLS & SHOP SUPPLIES SOSMETAL PRODUCTS INC. D14 D13 D12 D10 B D10 DRILLING TIPS DRILLING PROBLEMS SOLUTION - Use Drills with wider flutes and/or faster helix angle. - Consider polished flutes. - Withdraw drill at regular intervals to clear chips. - If chips are not broken up, consider heavier feeds, or chip breaker design. - Repoint or replace drill. - Check for excessive speed, or incorrect coolant, excessive run out as drill enters work. - Use adequate holding or clamping device. - Reduce feed. - Check for correct lip clearance. - Use proper type of drill/point for application. - Replace before dulling occurs. Check feeds, speeds, and No. 5 for premature dulling. - Repair or replace. - Check for positive secure fit. - Increase feed. - Consider use of chip breaker design drill and/or chip breaker point grind. - Use soft lead, brass, plastic, etc. hammer. - Handle with care. - Repoint or replace with properly pointed drill. - Repair, if possible; consider use of bushing. - Tighten and hold securely. - Repoint or replace with proper pointed drill. - Reduce feed. - Correct and adjust. - Correct and adjust. - Review and adjust. - Review requirements and conditions. - Repoint or replace with properly pointed drill. - Repoint or replace with properly pointed drill. - Reduce feed. - Repoint or replace with pointed drill. - Correct and adjust. - Reduce speed. - No final remedy if this condition is prevalent; lower feeds and speeds may help. DIAGNOSIS 1. Flutes clogged up with chips, drill binds in hole, common in deep holes. 2. Drill binding due to worn outer corners. 3. Work insecurely held. 4. Excessive feed. 5. Improper point. 6. Drill is dull. 1. Shank or socket damaged. 2. Drill not properly seated in socket. 1. Insufficient feed. 2. Improper style of drill and/or point. 1. Using hard object to tap drill into point. 2. Dropping, mishandling drill. 1. Drill point off center. 2. Machine spindle not rigid or not running true. 3. Work piece loose and/or vibrating. 1. Incorrect point grind and/or dull drill. 2. Excessive feed. 3. Incorrect or insufficient coolant. 1. Coolant not reaching point or incorrect or insufficient coolant. 2. Speed too high and/or feed too low. 3. Wrong type of point and/or drill for apps. 1. Insufficient lip clearance. 2. Point thinned too much. 3. Excessive feed. 1. Excessive lip clearance and/ or heel relief. 1. Insufficient or incorrect coolant. 2. Excessive speed. 3. Scale, hard spots encountered in material. PROBLEM BROKEN DRILL BROKEN TANG CHIPS NOT BREAKING UP DAMAGED POINT OVERSIZE HOLE ROUGH HOLE POOR TOOL LIFE WEB SPLITS CHIPPED LIPS BROKEN OUTER CORNERS TIPS AND TECHNIQUES Overcoming problem areas, as well as sound principles of drill usage. FEEDS & SPEEDS Different drilling conditions make it impossible to develop any rigid rules for feeds and speeds. The following tables contain guidelines which can be utilized when drilling standard materials. Also, the following "rules of thumb" can be used to determine proper feeds and speeds for drilling ferrous materials (note: varying conditions can easily require adjustments): • Feed equals .001" per revolution for every 1/16" of drill diameter, plus or minus .001" on the total. • Speed equals 80 surface feet per minute in 100 Brinell hardness material, and the speed should be reduced 10 surface feet per minute for additional 50 points Brinell hardness. • Feed and speed rates should be reduced up to 45 to 50% when drilling holes deeper than 4 drill diameters. DIAMETER OF DRILL FEED (INCHES) (INCHES PER REVOLUTION) Under 1/8 .001 to .003 1/8 to 1/4 .002 to .006 1/4 to 1/2 .004 to .010 1/2 to 1 .007 to .015 1 and over .015 to .025 RECOMMENDED SPEED MATERIAL (SFM) Aluminum and its Alloys 200-300 Brass and Bronze (ordinary) 150-300 Bronze (High Tensile) 70-150 Die Castings (Zinc Base) 300-400 Iron — Cast (soft) 75-125 Cast (medium hard) 50-100 Hard Chilled 10-20 Malleable 80-90 Magnesium and its Alloys 250-400 Monel Metal or High-Nickel Steel 30-50 Plastics or Similar Materials 100-300 Steel — Mild .2 carbon to .3 carbon 80-110 Steel .4 carbon to .5 carbon 70-80 Tool 1.2 carbon 50-60 Forgings 40-50 Alloy — 300 to 400 Brinell 20-30 High Tensile (Heat Treated) 35 to 40 Rockwell "C" 30-40 40 to 45 Rockwell "C" 25-35 45 to 50 Rockwell "C" 15-25 50 to 55 Rockwell "C" 7-15 Stainless Steel Free Machining Grades 30-80 Work Hardening Grades 15-50 Titanium Alloy Sheet 50-60 Titanium Alloys Ti-75A (Commercially Pure) 50-60 RS-120 40-60 Ti-150A 40-50 Ti-140A 30-40 RC-130B 30-40 MST 6A1-4 Va. 20-35 MST 3A1-5 Cr. 10-20 NOTE: It is best to start with a moderate speed and feed, increasing either one, or both, after observing the action and condition of the drill. RECOMMENDED SPEEDS FOR STANDARD MATERIAL WITH H.S.S. DRILLS RECOMMENDED FEEDS FOR VARIOUS DIAMETER DRILLS
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