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Build: One-piece, heat-treated 4140 alloy-steel body; CNC-machined pin.
Cutting structure: 5.5 mm tungsten-carbide inserts with hand-ground relief for cool cutting and clean evacuation.
Best suited: Sand, clay, shale, soft limestone; water-well, geothermal, environmental holes.
Connections: API Reg standard; broad API/IF/Mayhew coverage for drop-in compatibility.
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The 3 7/8" step drag bit is tuned for fast, low-risk starts in plastic formations. Its three-wing stepped profile bites quickly, then sheds cuttings in smooth ribbons so the rig hears a low, even rumble instead of chatter. On sands, clays, and soft shales you’ll see high ROP at modest WOB and stable torque, which keeps pilot holes straight and gauges honest. Compared with chevron style, step wings are more aggressive—ideal when footage and schedule matter—while gauge protection and pocket-milled carbide preserve edge life. Whether you pump mud or air, crews get clean returns and fewer unplanned trips. For RC sampling programs or sticky overburden, we match porting and pin to your string to keep samples faithful and hole cleaning predictable.
Monolithic strength: One-piece 4140 body resists wing fatigue and pin wash—built for repeated make-and-break on field rigs and trailer units.
Edge that stays cool: 5.5 mm carbide inserts seated in milled pockets with relief hand-ground behind the edge; results in cooler cutting and cleaner, heavier chips that are easier to log.
Faster penetration, straighter pilots: Step geometry starts quicker than chevron while long bearing surfaces help hold gauge in silty clays.
Plug-and-play threading: Ship in 2 3/8" API Reg by default; API Reg/IF/Mayhew libraries available to eliminate adapters on site.
Process-led QC: Heat-treat, CNC threading, and insert seating align with industry good practice for water-well and HDD pilots—less downtime, cleaner invoices.
| Parameter | Value |
|---|---|
| Nominal size | 3 7/8" (98 mm) |
| Type / wings | Step, 3-wing |
| Body material | Heat-treated 4140 alloy steel (one-piece) |
| Inserts | Tungsten carbide, 5.5 mm thickness |
| Standard pin | 2 3/8" API Reg (others on request) |
| Operating guidance | 60–80 RPM, light WOB (step style) |
| Formation window | Soft to medium formations (sand, clay, shale, soft limestone) |
| Weight (indicative) | ~5 kg for 98 mm class (supplier benchmark) |
| Size availability | 2"–17 ½" standard; customs up to 24" offered by peers |
| Variants | Chevron (harder/abrasive) and reverse-circulation drag bit options |
Formation & bit style: Use step drag bit in soft→medium formations; move to chevron when abrasivity increases (soft sandstone/shale). Expect higher ROP with step, longer life with chevron.
RPM/WOB envelope: Start at 60–80 RPM with light WOB; tune by torque and returns. Harder intervals may need lower RPM and more WOB if switching to chevron.
Wings trade-off: 3-wing drills faster; 4-wing tracks straighter and can last longer in mixed ground.
Thread compatibility: Maintain drop-in with 2 3/8, 2 7/8, 3 ½, 4 ½, 6 5/8" API Reg, plus IF/Mayhew families for legacy strings.
Logistics norms: 3 7/8" class bits often ship ~5 kg, carton/wooden crate packaging; supplier lead-times and warranties vary 6–36 months—specify your stocking policy to reduce rig idle.
We build on the proven recipe—4140 one-piece body + 5.5 mm carbide—and control the CNC pin, heat-treat, and pocket milling to ensure bond integrity and gauge life. That means crews spend time drilling, not swapping adapters or troubleshooting washed pins. Our catalog covers 2"–17 ½" as standard, with fast-turn custom threads to match your inventory, and reverse-circulation drag bit options where sampling demands it. For planners, we provide formation-specific start parameters, pin compatibility charts, and test logs to de-risk mobilizations and keep footage predictable month-to-month.
Q1. Can I run this well drilling drag bit in abrasive sandstone?
It will penetrate, but wear accelerates. For abrasive/harder zones, step down in RPM or switch to chevron (or PDC where applicable) to protect economics.
Q2. What’s the recommended startup window?
Begin around 60–80 RPM with light WOB; watch torque and returns, then trim WOB before RPM. This keeps cutters cool and maintains straight pilots.
Q3. What pin threads are available—can I avoid adapters?
Default is 2 3/8" API Reg for this size. We also supply 2 7/8, 3 ½, 4 ½, 6 5/8" API Reg and IF/Mayhew families for drop-in compatibility with your string.
Q4. Do you support a 20" drag bit later in the program?
Yes—the series covers from 2"–17 ½" commonly; peers offer customs up to 24". Share formation and thread, and we’ll quote a 20" drag bit to spec.
The 3 7/8" step drag bit is tuned for fast, low-risk starts in plastic formations. Its three-wing stepped profile bites quickly, then sheds cuttings in smooth ribbons so the rig hears a low, even rumble instead of chatter. On sands, clays, and soft shales you’ll see high ROP at modest WOB and stable torque, which keeps pilot holes straight and gauges honest. Compared with chevron style, step wings are more aggressive—ideal when footage and schedule matter—while gauge protection and pocket-milled carbide preserve edge life. Whether you pump mud or air, crews get clean returns and fewer unplanned trips. For RC sampling programs or sticky overburden, we match porting and pin to your string to keep samples faithful and hole cleaning predictable.
Monolithic strength: One-piece 4140 body resists wing fatigue and pin wash—built for repeated make-and-break on field rigs and trailer units.
Edge that stays cool: 5.5 mm carbide inserts seated in milled pockets with relief hand-ground behind the edge; results in cooler cutting and cleaner, heavier chips that are easier to log.
Faster penetration, straighter pilots: Step geometry starts quicker than chevron while long bearing surfaces help hold gauge in silty clays.
Plug-and-play threading: Ship in 2 3/8" API Reg by default; API Reg/IF/Mayhew libraries available to eliminate adapters on site.
Process-led QC: Heat-treat, CNC threading, and insert seating align with industry good practice for water-well and HDD pilots—less downtime, cleaner invoices.
| Parameter | Value |
|---|---|
| Nominal size | 3 7/8" (98 mm) |
| Type / wings | Step, 3-wing |
| Body material | Heat-treated 4140 alloy steel (one-piece) |
| Inserts | Tungsten carbide, 5.5 mm thickness |
| Standard pin | 2 3/8" API Reg (others on request) |
| Operating guidance | 60–80 RPM, light WOB (step style) |
| Formation window | Soft to medium formations (sand, clay, shale, soft limestone) |
| Weight (indicative) | ~5 kg for 98 mm class (supplier benchmark) |
| Size availability | 2"–17 ½" standard; customs up to 24" offered by peers |
| Variants | Chevron (harder/abrasive) and reverse-circulation drag bit options |
Formation & bit style: Use step drag bit in soft→medium formations; move to chevron when abrasivity increases (soft sandstone/shale). Expect higher ROP with step, longer life with chevron.
RPM/WOB envelope: Start at 60–80 RPM with light WOB; tune by torque and returns. Harder intervals may need lower RPM and more WOB if switching to chevron.
Wings trade-off: 3-wing drills faster; 4-wing tracks straighter and can last longer in mixed ground.
Thread compatibility: Maintain drop-in with 2 3/8, 2 7/8, 3 ½, 4 ½, 6 5/8" API Reg, plus IF/Mayhew families for legacy strings.
Logistics norms: 3 7/8" class bits often ship ~5 kg, carton/wooden crate packaging; supplier lead-times and warranties vary 6–36 months—specify your stocking policy to reduce rig idle.
We build on the proven recipe—4140 one-piece body + 5.5 mm carbide—and control the CNC pin, heat-treat, and pocket milling to ensure bond integrity and gauge life. That means crews spend time drilling, not swapping adapters or troubleshooting washed pins. Our catalog covers 2"–17 ½" as standard, with fast-turn custom threads to match your inventory, and reverse-circulation drag bit options where sampling demands it. For planners, we provide formation-specific start parameters, pin compatibility charts, and test logs to de-risk mobilizations and keep footage predictable month-to-month.
Q1. Can I run this well drilling drag bit in abrasive sandstone?
It will penetrate, but wear accelerates. For abrasive/harder zones, step down in RPM or switch to chevron (or PDC where applicable) to protect economics.
Q2. What’s the recommended startup window?
Begin around 60–80 RPM with light WOB; watch torque and returns, then trim WOB before RPM. This keeps cutters cool and maintains straight pilots.
Q3. What pin threads are available—can I avoid adapters?
Default is 2 3/8" API Reg for this size. We also supply 2 7/8, 3 ½, 4 ½, 6 5/8" API Reg and IF/Mayhew families for drop-in compatibility with your string.
Q4. Do you support a 20" drag bit later in the program?
Yes—the series covers from 2"–17 ½" commonly; peers offer customs up to 24". Share formation and thread, and we’ll quote a 20" drag bit to spec.
