Drill Bits

Back to Main MenuDRILL BIT CLASSIFIER Drill Bit Classifier Drill Bit Classifier DRILL BIT CLASSIFIER 000-4. 20. 26 171/2 91/2. 97/8. 81/2.000 2.000 2.000 2. 16.000-5.000-5. rpm Special features/ usage* 1.000-4. 131/2.000 2. 143/4. 83/4. 61/4. 181/2.000 2. 171/2.000-5. 26. 121/4 10 5/8 121/4 171/2 121/4 81/2. 63/4 97/8 171/2.Security DBS Bit Name IADC code Size range.000-5. 121/4 121/4 77/8. 61/2. 26. 16.000-5.000 2. in. 22. 115/8 57/8. 11 61/8. 17.000 1. 121/4 77/8. 14 3/4.000-5. 28 105/8. 6. 23.000 350-80 200-80 200-80 W 2. 181/2. 133/4. 131/2.000 2.000 200-80 S 1.000-4. 97/8. 61/4.000-5. diameter Recommended rotary speed.500 200-80 350-80 240-80 200-80 180-80 350-80 180-80 300-80 180-80 180-80 160-60 G BCGLMR MG MG G G G G S G S Soft and Soft Sticky Steel tooth roller cone bits 111 SS33SG 115 SSD33SG S33SF PSF 115 116 116 ERA MPSF ERA 1RD MPSF MPSF2 S33SGF S33G S33GF S44G S33F S33TGF S4TJ 117 115 117 127 117 125 127 135 126 127 131 121/4. 83/4. 83/4. 81/2. 22.000-5.000 2. 24. lb/in. 171/2. 81/2.500 2. 121/4.000-5.000-5.000-5.500-4. 28 G Page 1 S3SJ .000-5. 24. 77/8. Recommended WOB. 21.000 2.000 2. 97/8. 23.000 350-80 MB 1. 000 1. 121/4 81/2. diameter Recommended rotary speed.000 2.000 1.000-5. 121/4 43/4. 171/2.000-4. 17. 81/2.000 350-80 160-70 350-80 160-70 350-80 250-80 280-80 160-70 250-80 250-80 160-70 160-70 160-70 160-70 250-70 160-70 MB BX MBX BX MBX MBX MBXGW BX BCGLMRX BCGLMRXW GLRX GLRY GLRX GLRX BCGLMRX GLRY Insert roller cone bits SS80 S80F SS81 S81F SS82 SS82 FD SS83 FD S82F ERA 03 ERA 03D ERA 07 ERA 07C ERA 07D ERA 07RD ERA 13 ERA 13C . lb/in. 16.000 1. 83/4.000-5.000 1. 171/2. 16. 24.000-5.000 2. 28 121/4 121/4 61/2. 97/8. 17. rpm Special features/ usage* Bit Name IADC code S4J SS44G S44GF S44F 131 135 137 137 6.000-4.000 1.000 2.000-4.000-4.000-6.000-5.000 1. 115/8.500 2. 121/4 121/4.Size range.000 160-60 300-80 150-60 150-60 S MBG G 415 417 425 427 435 437 447 437 417 417 427 427 427 425 437 437 16. 121/4.500-5. 171/2. 81/2. 24 81/2. 83/4. 143/4.500-5. 22.500 2. 20. 121/4 77/8 1.000-5.000-4.000-5.000 1.000 1. 83/4.000 1.500-5.500-5.000-6. 81/2 77/8 121/4 121/4 77/8.000-4. 105/8. 26 81/2 171/2 77/8.000-5.000 1. 121/4 121/4 121/4 77/8. 6 2.000 1. in.000 1.500-5.000 1. Page 2 Security DBS Recommended WOB. 000 2. Bit Name IADC code ERA 13D ERA 13RD ERA 14C ERA 17 ERA 17RD SS82F S82CF HZS82F HZSD82F SS80F ERA D17D ERA D17R ERA 17D S83F SS83F 437 435 437 447 445 437 437 437 437 417 447 445 447 447 447 121/4 121/4 77/8 77/8.000-5. 121/4 81/2.000 500-2.000-5.000 2.000-5.000 1.000 2. 121/4 121/4.000 500-2. 171/2 81/2 181/2 Recommended WOB.000-5. in.000-5. 61/4.000-5.000 1. 97/8 143/4.000-5.500 1.000 160-70 160-70 160-70 250-70 350-80 250-80 160-70 140-70 140-70 160-70 250-70 350-80 250-80 140-60 250-80 GLRX GLRX GLRY BCGLMRX BCGLMRX MBX BY HGBX HGBW GBM BCGLMRXW BCGLMRXW MWBXGC BX MBXGW 500-2.500 1. 83/4 61/8.000 2. 6.Security DBS Size range.000 500-2. 83/4.000-5.000 500-2. 97/8.500 1.500 1.000 1.000-5.000-5. 121/4 81/2.500 1.000 60-400 60-400 60-400 60-400 60-400 60-400 MVW MVW MVW MVW MVW MVW PDC drill bits Page 3 FM2446 FM2466 FM2643 FM2862 FM2365 FM2563 . diameter Recommended rotary speed.000 350-2. 123/8 81/2. 61/2. 63/4. 81/2.000-5.000 2. lb/in. 83/4.000 1. 61/2 6 1/8 97/8 121/4 121/4 121/4 77/8. 61/8.000-5.000-5. 121/4 M131 M111 M331 M121 M421 M121 121/4 121/4 57/8.000-5.000-5. 81/2. rpm Special features/ usage* 1. 141/2.500 200-3400 500-2. 16.000 200-3. 61/8.000 500-2. 97/8 83/8. 81/2. 81/2. 81/2 81/2.000 500-2. 61/4. 121/4 81/2. 81/2.000 350-2. 121/4.000 350-2.000 500-2. 121/4 83/8. 16.Bit Name IADC code FM2648 FM2566 B10-25 FM2565 FM2465 PD-5 FM2565 PD-4HS FM2365 FM2365 FM2662 FM2664 FM2545 FM2662 FS2441 FS2461 FS2463 FS2465 FS2545 FS2565 FS2645 FS2563 FS2543 M231 M323 M434 M223 M323 S422 M423 S423 M224 M124 M122 M423 M333 M323 S432 S322 S323 S424 S334 S424 S434 S323 S133 Size range.000 500-2.000 500-2. 171/2 121/4 Page 4 Security DBS Recommended WOB.000 500-2. 97/8. diameter Recommended rotary speed. 63/4. 97/8. 83/4. 121/4.000 500-2. 171/2 77/8. 83/8. 81/2. lb/in.000 500-2. 121/4. in. 121/4. 61/2.000 60-400 60-400 250-1400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 MVW MVW MN MVW MVW M MVW M MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW . 97/8. rpm Special features/ usage* 500-2.000 500-2.000 500-2. 97/8. 12. 81/2. 97/8. 97/8 77/8. 171/2 97/8 121/4 171/2 83/4 97/8 121/4 6. 16. 121/4 121/4 81/2.000 500-2. 97/8 97/8. 83/8 6.000 200-4. 121/4 81/2. 143/4 81/2 81/2 81/2.000 500-2. 143/4.000 500-2. 83/4.000 500-2.000 500-2.000 500-2. 500 50-150 F PDC coring bits CD 502 CD 73 FC264 CSP 107 CS93 FC244LI Surface set diamond coring bits CSD120 S134 Page 5 .000 200-3.Security DBS Size range.000 60-400 60-400 60-200 60-200 60-400 60-400 MVW MVW MVW MVW DVW DVW M132 M233 M233 S234 S132 M243 6-121/4 6-121/4 6-121/4 6-121/4 4-81/2.000 200-2. 17. 16. 131/2.000 500-2.500 250-3. diameter Recommended rotary speed.500 250-3.500 50-150 50-150 50-150 50-150 50-150 50-150 F F F F F 6-121/4 250-3. 121/4. Recommended WOB. 22 26 6.000 500-2.000 500-2. in. 61/8 6-121/4 500-2. rpm Special features/ usage* Bit Name IADC code FS2663 FS2467 FS2665 FS2661 SE3442 SE3461 S323 S424 S124 S122 M432 M422 12.500 250-3. 51/4-121/4 81/2-121/4 250-3.500 250-3. 171/2 61/8 20.500 250-3. lb/in. 16.000-6. 121/4 81/2. 61/4.000 2.000-6. 97/8. Page 6 Security DBS Recommended WOB. 63/4.Bit Name IADC code Size range. 171/2.000-6. 77/8. 97/8.000 2. 61/8. 121/4 63/4. 83/4.000 2.000 1. 81/2. 105/8. 121/4.000-6.000 2. in.000-6. 61/4 81/2. 26 43/4.000 1.000 2. 83/4.000 1. 22 57/8. 83/4.000-6.000-6. 57/8.000 3. 61/4. 121/4 121/4 12 81/2. 81/2. 24.000 3. 121/4.000-6. 121/4 . 61/2. 121/4 43/4.000-6. 97/8. 171/2.000 1. 61/8.000-6. 77/8. 23 81/2.000 1. 121/4 81/2. 12. 77/8. lb/in.000-5. 77/8. 171/2 61/8. 61/2.000-6.000 2.000 300-80 140-50 MB BX 2. diameter Recommended rotary speed. 97/8. 121/4.000 140-50 300-80 250-80 250-80 120-50 250-80 120-50 120-50 120-50 300-80 220-80 100-40 BW MBW MBXG MBXG MBXG WMBXC HGBX BX BY MB MB BX 2.000-5. 97/8.000-6. 6. 143/4 171/2. 97/8 97/8 81/2. 23.000 2.000-5. 6.000-6. 143/4.000 200-80 200-80 100-40 MBXG MBXGW BYG Soft-Medium Insert roller cone bits SS84 S84F 515 517 S84FD SS84D SS84F SS84FD SS85F ERA 22D HZS84F S85F S85CF SS85 SS86 S86F 517 517 517 517 527 517 517 527 527 525 535 537 SS86F SS86FD S86CF 537 537 537 81/2. 83/4. 83/8. rpm Special features/ usage* 1. 151/2. 171/2 81/2. 61/8.000-6. 000 3.000-6.000 2. 6. 121/4 77/8 43/4. 91/2. 121/4 Recommended WOB.000 2.000-6. lb/in. 11 77/8. 61/2.Security DBS Bit Name IADC code S86FD ERA 33C SS88C S88F S88CF S88CFH S88FA ERA 22C ERA22R ERA 25 ERA 25C ERA 33 ERA 33CD ERA 33D ERA 18C ERA 22 ERA 22R ERA D22D ERA D25D ERA D33D 537 537 545 547 547 547 547 517 517 527 527 537 537 537 517 517 515 517 527 537 Size range.000 3.000 2. diameter Recommended rotary speed. 61/4.000 1. in.000-5.000 2.000 2.000 2.000-6. 97/8 81/2 81/2 77/8 77/8.000 2.000 3.000-5.000 2.000 2.000-6.000-7.000-6. 83/4.000 3.000 1.000-6. 81/2.000-6.000-6.000-6.000-7. 97/8 97/8.000-7.000-6.000 100-40 100-40 220-80 80-40 80-40 80-40 80-40 140-50 300-80 120-50 120-50 200-40 200-80 200-80 140-50 200-50 300-80 140-50 120-50 200-80 BXW BYG MBPG BX BY YB AB GLRY MBXC GLRX BGLRY BGLRX BXGW BXGW GLRY BCGLMRX BCGLMRX BGLMRXW BGLMRXW BCGLMRXW Page 7 . 81/2.000-6.000 1. 77/8 77/8 77/8 77/8 121/4 77/8 77/8. 97/8.000 2. 11 81/2.000 3.000-7.000-6. 121/4 121/4 81/2 81/2 81/2.000 2. rpm Special features/ usage* 3.000-6. 83/4.000-6. 83/8. 43/4 97/8. 121/4. 81/2 77/8. IADC code Page 8 Security DBS Recommended WOB. 41/2.500 500-2.500-3. 6.500 1. 143/4 57/8. 81/2. 143/4 121/4 77/8.000 500-2.000 500-2.500 500-2. 121/4 57/8. 91/2. 12.500 500-2. 6.500 500-2.500 200-3. diameter Recommended rotary speed. 101/2. 81/2 12. 121/4. 83/4. 83/4 83/8. 12.500 500-2. 105/8 81/2.000 80-450 60-400 80-450 60-400 60-400 60-400 60-400 60-400 60-400 80-350 80-450 60-400 60-400 HM M HM MVW MVW MVW MVW MVW MVW MW HMW MVW MVW Fish tail bits FM2443 FM2445 FM2445 FM2445 FM2461 FM2463 M431 M121 M331 M131 M221 M421 61/8. 37/8. 63/4.500 500-2.000 500-2. lb/in. 61/2 6 PDC drill bits HZ23-2 TD19H HZ23-1 FM2943 FM2865 FM2745 FM2846 FM2841 FM2943 B35+2 HZ35+2 FM2443 FM2445 . in. 63/4 61/4 81/2 97/8. 61/8. 83/4. 83/8.000 500-2. 61/2. rpm Special features/ usage* 500-2. 61/8. 97/8. 61/4. 97/8. 121/4 6. 121/4 97/8 61/8 M232 M223 M342 M333 M423 M433 M433 M433 M333 M432 M432 M333 M334 53/4. 41/8.Bit Name Size range. 81/2. 6. 81/2.500 500-2. 63/4. 141/2 31/2.000 1200-2700 500-2.000 60-400 60-400 60-400 60-400 60-400 60-400 MVW MVW MVW MVW MVW MVW 500-2. 77/8. 83/8.000 500-2.500 500-2. 500 500-2.000 500-2.Security DBS Size range. diameter Recommended rotary speed.500 500-2.500 500-2. in.500 80-140 50-150 F F PDC coring bits CD 93 FC264LI Page 9 Bit Name IADC code . 63/4 6 121/4 16.500 500-2.500 250-3. 61/4.500 500-2.000 500-2.500 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 60-400 MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW MVW DVW M233 M343 6-121/4 81/2-121/4 250-3. 83/4 97/8 121/4 61/8.000 500-2.500 500-2.500 500-2.500 500-2. 171/2 16 97/8 121/4 6 500-2.500 500-2. rpm Special features/ usage* FM2461 FM2545 FM2545 FM2546 FM2641 FM2641 FM2641 FM2645 FM2665 FM2665 FM2743 FM2633 FM2631 FS2743 FS2863 FS2963 FM2765 FM2765 SE3641 M222 M433 M333 M433 M232 M432 M332 M333 M423 M323 M333 M443 M442 S243 S223 S223 M424 M324 M332 121/4 77/8 83/4.500 500-2. 97/8 81/2 6. 81/2. 61/8 63/4 61/2 77/8.500 500-2.000 500-2.000 500-2. 83/4 77/8.000 500-2.500 500-2. lb/in. 61/2. Recommended WOB. 97/8.500-7. 12. 105/8.000 3.000 3.000 3.000 4.000 4.000 80-40 80-40 150-80 80-40 14824 80-40 80-40 150-80 80-40 80-40 70-40 70-40 BXW AB MB BY BYW BX BY MB BX BXW BY BYW Surface set diamond coring bits CB17 M613 6-121/4 M84 M84F 615 617 M84FD MAF MM88 M84CF M84CFD M85F M86CF M89T M89TF M89TFD M89F M89FD 617 617 625 627 627 627 627 627 627 627 637 637 11 5/8.000-7.000 2.000 2. diameter Recommended rotary speed.000 3.000 3. 81/2. 51/2. 61/8.000-7. in. 63/4. 171/2 43/4.000-7. 77/8. 81/2. 61/2.000-7. IADC code Recommended WOB. rpm Special features/ usage* 250-3. 77/8.000-7.500 80-140 F 3. 6.Bit Name Size range. 61/2.000 3. 61/4. 83/4. 121/4 83/8.000-7.500-7.000 300-80 80-40 X BX 3.500-7. 63/4. 81/2.500-7. 17. 11 81/2. 91/2. 121/4 77/8 121/4 77/8. 121/4 97/8 Medium Insert roller cone bits Page 10 Security DBS .500-7. 63/4.000-7. 61/4.000 3. 83/8.000-7. lb/in. 77/8. 83/4 77/8 171/2 57/8. 8 3/4. 91/2 77/8.000-7. 83/4 61/2. 83/4. 83/4.000 3. 500 500-2. diameter Recommended rotary speed.500 250-3.500 500-2. lb/in. Recommended WOB. in.000 70-40 70-40 80-40 BY BWY BCGLMRXW M221 63/4 . 61/4 61/8.500-2. 61/4 121/4 4.500 60-400 60-400 60-400 60-400 60-400 MVW MVW MVW MVW MVW M233 M334 M232 M333 M343 6-121/4 6-121/4 6-121/4 6-121/4 81/2-121/4 250-3.500 250-3.500 500-2.500 60-400 MVW M433 M332 M433 M323 M324 97/8 121/4 81/2 143/4 121/4 500-2.500 90-160 90-160 90-160 90-160 50-150 F Fish tail bits FM2563 PDC drill bits FM2844 FM2844 FM2845 FM2863 FM2865 PDC coring bits F F Page 11 FC284 CD 104 CD 202 CMP ZI FC274LI .500 500-2.000 3.500 250-3. rpm Special features/ usage* Bit Name IADC code HZM89F HZMD89F ERA D44D 637 637 617 61/8.000-7.500 250-3.000-7.000-7.Security DBS Size range.000 4. 33/4 57/8. 121/4. 16. 83/8.000 80-1000 80-1000 80-1000 80-1000 80-1000 80-1000 IMN IMN IMN MN IMN IMN 2. 43/4. 171/2. Recommended WOB. 6.000 300-3. 121/2 31/2. 81/2.500 3.000-6. diameter Recommended rotary speed.500 3.000 300-3.000-4. rpm Special features/ usage* 300-3. 26 43/4. 81/2 Medium-Hard Steel tooth roller cone bits M44NG MM44NG M44NF M44NGF M4N 215 215 216 217 211 77/8. 57/8. 61/8.000-6. in.000 300-3. 61/4. 61/8. 81/2.000 300-3. 83/4. 61/4.000 2. 57/8. 81/2 81/2. 61/2 81/2. 57/8. 81/2 61/2. 55/8. 121/4 6. 6.000 300-3. 121/4 Page 12 Security DBS . lb/in. 121/4 41/8.Bit Name IADC code Size range.000-6. 53/4.500 120-40 250-80 110-40 110-40 G MGB S G Surface set diamond bits TT521 TT561 TBT17 TB16 TT593 TBT703 M622 M624 M634 M713 M724 M734 57/8. 500 250-3.500 250-3. diameter Recommended rotary speed.500 110-150 110-150 110-150 110-150 110-150 I W I I I PDC coring bits FC284LI FCi264LI Surface set diamond coring bits CT 303 CT 313 CT 103 CT 403 CT 93 M623 M623 M623 M624 M623 Page 13 .Security DBS Bit Name Size range.500 500-3.500 50-150 50-150 F F 6-121/4 6-121/4 6-121/4 6-121/4 6-121/4 250-3.500 250-3.000 500-3. lb/in.500 250-3.500 250-3. rpm Special features/ usage* PDC drill bits FM2643i FM2762i FM2843i SE3641i M343 M322 M343 M342 51/2-6 121/4 121/4 53/4-81/2 500-3. IADC code Recommended WOB.000 100-400 100-400 100-400 100-400 VWM VWM VWM DVWM M343 M343 81/2-121/4 81/2-121/4 250-3. in.500 500-3. 61/2 77/8 56/8.000-7. 81/2. 171/2 3. 97/8.500 4.500 65-35 65-35 Y B M442 M442 M443 M432 M442 M443 M442 M342 M343 57/8.000 500-3. 61/8. 83/4. 61/8.000 500-2. 81/2.500 3. 121/4 81/2 6. 6.000-6. IADC code Recommended WOB. 121/4 57/8 6.500 500-2. 83/4. 121/4 81/2 97/8 83/8-81/2 83/8-81/2 500-2. 61/2. rpm Special features/ usage* Hard Steel tooth roller cone bits H77SG H77SGF H7 335 337 331 81/2.000 500-2. 61/2. diameter Recommended rotary speed.000 500-2. 6. in.500 500-2.500 3. 57/8.000-7. lb/in.Bit Name Size range.000 500-3. 9. 97/8 77/8. 11 4.000-6. 63/4.500 300-3.500 80-40 80-40 80-40 G G G 717 737 77/8. 63/4.000-6.000 60-450 60-450 60-400 60-450 60-400 60-400 60-400 100-400 100-400 MVW MVW MVW MVW MVW MVW MVW MVW MVW Insert roller cone bits H83F H87F PDC drill bits FM2821 FM2821 FM2921 FM2941 FM2831 FM2933 FM2931 FM2841i FM2843i Page 14 Security DBS . 61/8. 000 100-400 100-400 100-400 100-400 100-400 MVW MVW MVW MVW DMVW M343 M343 81/2-121/4 81/2-121/4 250-3.500 500-3. diameter Recommended rotary speed.500 250-3. lb/in.Security DBS Size range.500 50-150 50-150 F F 57/8.000 500-3. in.000 300-3.000 80-1000 80-1000 IMN MN 6-121/4 6-121/4 250-3.000 500-3. rpm Special features/ usage* Bit Name IADC code FM2845i FM2941i FM2943i FM2945i SE3841i M344 M442 M443 M444 M342 83/8-81/2 83/8-81/2 83/8-81/2 121/4-171/2 83/8-81/2 500-3. 61/8. 81/2. 121/4 300-3.500 100-130 100-130 PDC coring bits FCi274LI FCi284LI Surface set diamond bits TBT26 TB26 M831 M811 Surface set diamond coring bits CB 303 CB 401 M613 M613 Page 15 . 83/8 61/8.000 500-3. Recommended WOB. 83/8.500 250-3. 000 80-1000 IMN 300-3.Bit Name Size range. 83/4. 11. 121/4 57/8-81/2 57/8-121/4 57/8-81/2 300-3. 57/8.500 55-40 50-30 B BY 4. 133/4 171/2 Surface set diamond bits TI2352 M843 Fi2241 Fi2641 Fi2841 M841 M841 M841 41/8. 6.000 55-40 Y Extremely Hard Insert roller cone bits H89F H100F 817 837 H100 835 77/8.000 300-3. 97/8. 81/2.000-7. IADC code Recommended WOB.500-7. diameter Recommended rotary speed. 97/8 57/8. 9.000 80-1200 80-1200 80-1200 VMT VMT VMT 6-121/4 250-3. in.500 50-70 G Suface set diamond coring bits CI352 M843 Page 16 Security DBS . 81/2.000-7. 61/2. rpm Special features/ usage* 4.500 300-3. 61/8. 83/8. 121/4.500 4. 51/2. lb/in. Thermally stable synthetic diamond (TSP) J.Deviation control E. medium (m).Enhanced cutting structure X.Mud motor application N.Gage/body protection (additional) H.Radial flow hydraulics S.Percussion drilling Q.Chisel tooth insert Y. Um. Uh V. light (l).Face discharge ports G.Page 17 *Special Feature Nomenclature: (Boldface indicates IADC convention) A.Air drilling application B.Other shape insert .Anti-whirl characteristics W.Cross flow hydraulics L.Two cone bit U.Conical tooth insert Z.Special bearing seal C.Horizontal steering application I.Lug pads M. Example: Ul.Extended jet (full length) F.Milling applications P.Jet deflection K.Center jet D.Lateral nozzles R. heavy (h).Standard steel tooth model T.Turbine drilling O.Cutter density. Surface set diamond (natural. PDC drill bit 6. mudstone.or semiabrasive layers like shale. siltstone. natural/TSP) drill bit 8. Roller cone coring bit 4. dolomite and anhydrite HARD: Hard and dense formation types with very high compressive strength and some abrasive layer like siltstone. interbedded with hard layers like sand. Insert roller cone drill bit 3. chalk and anhydrate MEDIUM: Hard formation types with moderate compressive strength. limestone. TSP. Fishtail drill bit 5. soft sticky): Formation types with low compressive strength and high drillability like clay. marl. but non. Surface set diamond (natural. chalk. TSP. shale. like shale. shale.Page 18 Bit Classifications: 1. sandstone and mudstone EXTREMELY HARD: Very hard and abrasive formation types like quartzite and volcanics . natural/TSP) coring bit SOFT (incl. sandstone. Steel tooth roller cone bit 2. anhydrite and sand MEDIUM-TO-HARD: Dense formation types with high and increasing compressive strength. sticky gumbo and unconsolidated sand SOFT-TO-MEDIUM: Formation types with low compressive strength. including very soft. salt and sand. PDC coring bit 7.