Straight Insert Tool Holder w/55° insert
This holder features a centered design (not offset to either side) and includes a 55° carbide insert, a hold-down screw, and a Torx key for installation. It has a 3/8″ square shank that fits standard 3/8″ tool posts. The straight tip design allows for general-purpose turning operations in either direction. The cutting tip is positioned 0.375″ from the bottom of the holder, which conforms to industry standards. The holder is constructed from case-hardened steel and finished with black oxide for enhanced durability and corrosion resistance.
Though more costly than traditional tools, each insert offers two usable cutting edges. When one edge becomes dull or chipped, simply rotate the insert 180° to access a new cutting surface—essentially providing two tools in one.
About the Carbide Inserts
While high-speed steel (HSS) tools remain the primary choice for miniature machine work due to their affordability and ease of resharpening, inserted-tip carbide tools offer significant advantages in specific applications. Carbide inserts excel in cutting harder materials, improving efficiency and tool life—making them invaluable in many professional machining environments.
Safety Note
Carbide inserts can produce extremely hot chips and may shatter under stress. Always wear appropriate eye protection and safety gear when using these tools.
Certain materials, such as tool steel, may form long, continuous chips that can wrap around the workpiece like steel wool. To minimize this, use a chip brush frequently or pause machining to remove chip buildup. These “bird’s nests” can ignite from hot chips, so maintain a clean workspace near the cutter.
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Insert Holder Material | Case Hardened Steel |
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Body Coating | Black Oxide |
Related products


80° RH and LH Tool Holders w/Carbide Inserts
These holders are available individually in right-hand and left-hand configurations, or as a matched pair. Each includes an 80° carbide insert, a hold-down screw, and a Torx® key for installation.
Specifications & Features:
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3/8" square shank, compatible with standard 3/8" insert tool posts
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5° offset angle provides better tool clearance for complex operations
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Tip height is 0.375" from the base, meeting industry standards
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Constructed from case-hardened steel with a durable black oxide finish
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80° inserts are ideal for roughing cuts
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55° insert holders are also available for sharper corner access
For example, when the holder is squared with the crosslide, it allows you to turn an O.D. up to a shoulder, then finish the shoulder by backing the tool out—while maintaining proper clearance throughout the cut.
Advantages of Inserted Tip Carbide Tools
Although more expensive than high-speed steel (HSS), carbide inserts offer key benefits:
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Each insert can be rotated 180°, giving you two cutting edges per insert
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Maintain a sharp edge when cutting exotic alloys or abrasive materials
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Enable faster cutting speeds and improved surface finishes
While HSS tools are ideal for general use due to their affordability and ease of resharpening, carbide tools are essential for challenging jobs, which is why they're widely used in professional machine shops.
Note: Tool orientation is based on the direction of chip flow. A right-hand tool has its cutting edge on the left, with chips exiting to the right.
Chip Breaker Update: The previously used straight-groove chip breaker is no longer available. Current inserts now come with the improved spider web-style chip breaker, as shown in the updated product images.


RH 55° and 80° 3/8″ Boring Bars w/Carbide Inserts
These 3/8" diameter boring bars feature a carbide insert secured with a Torx® screw and come complete with a Torx wrench. Choose between:
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A 55° right-hand insert, suitable for starting holes as small as 3/4", ideal for reaching sharp internal corners
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An 80° insert, which fits into a smaller 1/2" hole and offers added strength for roughing operations
Each holder measures 3-1/4" long and can bore to a depth of just over 2" when properly secured with two set screws. Manufactured from durable 1144 Stressproof® steel with a black oxide finish, these tools are available individually or as a discounted set.
Why Choose Carbide Insert Tools?
While high-speed steel (HSS) remains common for small machine tools due to its low cost and resharpenability, carbide inserts offer significant advantages in demanding applications:
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Longer-lasting edges when cutting hard metals like stainless steel, titanium, or abrasive materials such as carbon fiber
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Faster cutting speeds and greater efficiency
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Each insert can be rotated 180°, effectively giving you two cutting edges per insert
Although carbide inserts can't be resharpened, their durability and versatility make them a preferred choice in professional machine shops.
Note: The older straight-groove chip breaker insert is no longer available. Current inserts include the spider web-style chip breaker, as shown in the updated images here & here


Threading/Grooving Carbide Insert Tool Holder
Due to the variety of insert types and their cost, the holder is sold separately without inserts, allowing you to select only the specific inserts you need. The holder includes a clamp, 6-32 hold-down screw, and a 7/64" hex key for secure setup.
⚠️ CUSTOMER NOTICE — July 8, 2020
We’ve identified a potential issue affecting a small number of our Threading/Grooving Carbide Insert Tool Holders. Specifically, the cutting insert may not be securely clamped in place.
When tightening the clamp, the inside corner of the clamp may contact the step adjacent to the insert pocket, preventing full engagement with the clamping notch on the insert. This was caused by an early in-house clamp design that mistakenly used symmetrical angles on both sides of the clamp nose, rather than the intended asymmetrical design. This issue has since been corrected.
[caption id="attachment_33596" align="alignright" width="300"]
To resolve the issue immediately:
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Use a bench grinder or file to slightly grind down the back side of the clamp (see blue circle in the image).
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This will allow the clamp tip to clear the step (indicated by the red arrow), ensuring full contact and proper clamping of the insert.
⚠️ CAUTION: Chips coming off the carbide inserts can be very HOT! Use extreme caution. Carbide inserts can also shatter. For these reasons, proper protective eyewear and clothing are especially important when using these tools. Materials like tool steel can form long, stringy chips that wrap around the part. Use a chip brush frequently, or pause machining to clear debris. Accumulated chips, especially when hot, can ignite. Keep the area around the cutter clean and free of chip buildup.


Ceramic Insert Tool Holder
Designed for cutting hard materials like tool steel, this ceramic insert tool holder features a triangular insert mounted at a negative rake angle. The downward tilt of the insert provides proper side clearance, allowing you to use all six cutting edges—three per side—before needing a replacement. The 3/8" shank fits Sherline’s P/N 7600 tool post (not included). A clamp, hold-down screw, and 3/32" hex key are included for secure installation. Replacement inserts are available as (P/N 22659).
Why Use Ceramic Inserts?
Ceramic cutting tools are a powerful addition to the modern machinist’s toolbox. Though more brittle than high-speed steel (HSS) or carbide, ceramic inserts excel at cutting hardened steels and other tough materials, especially at higher spindle speeds. This makes them ideal for jobs that would otherwise be extremely difficult or impossible—such as turning down the shank of an end mill.
This insert’s large nose radius helps achieve an excellent surface finish, particularly when profiling.
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Each insert offers six usable cutting edges:
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Rotate 120° to access a new edge (3 per side), then
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Flip the insert for 3 more cutting points on the opposite face
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In comparison, traditional carbide inserts offer only 2–4 cutting edges, making ceramic inserts cost-effective over time, despite the higher upfront cost.
Usage Notes & Safety Information
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Ceramic inserts are brittle and should be used with proper technique to avoid chipping or breakage.
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Caution: Chips produced during cutting can be extremely hot—even red-hot. Use protective eyewear, gloves, and fire-safe clothing when operating.
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Some materials, such as tool steel, may form long, stringy chips that wrap around the part ("bird’s nest" effect).
Use a chip brush and stop the machine frequently to clear chips. These chip clusters can ignite if they come in contact with hot chips.