3/8" Diameter x 3/4" Length of Cut x 1/4" x 7" Flex Shank. Cylindrical Ball Shape with Double cut.. Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths.
(Options for 12" & 18" Lengths)Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
1/2" Diameter x 1" Length of Cut Cylindrical Ball Shape with Double cut.. Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths. (Options for 12" & 18" Lengths)
Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
1/4" Diameter Ball Shape with Double cut..with Optional Shank Diameter and Overall Length Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths.
Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
3/16" Ball Shape Double Cut with a 1/8" x 7" Flex Shank Carbide Burr
Optional:Flexible Shanks are available in 1/8" x 12" and 18" Lengths.
Flexible Shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths.
Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs.Available in all shapes and lengths. (Options for 12" & 18" Lengths) Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
1/2" Diameter Ball Shape with Double cut.. Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths.
Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
5/8" Diameter Ball Shape with Double cut.. Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths.
Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
3/4" Diameter Ball Shape with Double cut with Optional 1/4" or 3/8" Shank Diameter and Overall Length. Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Specials available in all shapes and lengths.
Please note: Because of the extreme application needed to use these type of tools carry's no warranty of use or product liability..
5/8" Diameter Ball Shape with Double cut..with a 3/8" x 12" Flex Shank.. Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths.
Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
1/4" Diameter (Oval Shape) with 3/16" x 7" Flex Shank with with Optional lengths 12" & 18". Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths.
Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
1/4" Diameter Oval Shape with Double cut..with a 1/4" x 7" Flex Shank Flexible shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths
Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
3/8"Diameter x 7" Flex Shank Egg Shape (Oval) with Double cut.. Flexible 1/4" shank Carbide Burrs are best suited to castings in areas that are difficult to reach with standard or long shank burrs. Available in all shapes and lengths.(Options for 12" & 18" Lengths) Please note: Because of the extreme application needed to use these types of tools carries no warranty of use or product liability.
Flex Shaft carbide burrs – flexible reach for tight spaces
Some jobs are simply impossible to reach with a rigid shank — internal casting pockets, deep bores inside assembled components, confined structural cavities. Flex Shaft carbide burrs solve this with a precision-engineered flexible steel shank that navigates obstructions and angles into tight spaces while still delivering full cutting power from the solid tungsten carbide head. Available in 6, 12, and 18-inch lengths.
18"
max shank length
1/4"
standard shank
USA
manufactured
Key features & benefits
True flexible steel shank
Precision-engineered flexible shank bends to navigate obstructions — access internal surfaces impossible to reach with rigid tools.
3 length options
Available in 6-inch, 12-inch, and 18-inch overall lengths — choose the reach you need for every application.
Solid carbide cutting head
Full tungsten carbide head delivers the same cutting performance as a rigid burr — flexibility does not compromise cutting power.
Double cut standard
All Flex Shaft burrs feature double-cut geometry — efficient material removal on ferrous and non-ferrous metals.
All major shapes available
Cylindrical, ball, oval, tree, flame — full shape range so you never compromise geometry for reach.
Flexible shank navigates into internal casting cavities rigid tools cannot enter
Deep bore finishing
bore deburringinternal surface work
18" length reaches bore depths impossible for standard tools
Assembled component access
engine internalsgearbox work
Avoid disassembly — flex shank reaches inside assembled units
Confined structural cavities
box section weld cleanuphull internals
Bends around obstructions to reach weld seams inside closed sections
HVAC & pipe work
duct deburringpipe interior work
Navigates bends and tight runs inside pipe and ductwork
Flex shaft vs rigid extended shank vs standard shank
Flex Shaft burr
vs
Rigid extended shank
Bends around obstructions
access
Straight line only — blocked by obstructions
Reaches inside assembled components
disassembly
Often requires disassembly for access
Up to 18" reach with full flexibility
length
Rigid shanks amplify vibration at length
Same solid carbide cutting head
performance
Same cutting head performance
Flex angle must stay within rated limits
limits
No angular limitation
Who should use Flex Shaft burrs
Engine builders
Internal casting & bore work inside assembled engines
Foundry workers
Deep internal casting pocket cleanup & flash removal
Shipbuilders
Internal hull weld seam access in confined spaces
HVAC technicians
Duct & pipe interior deburring around bends
Maintenance engineers
In-situ repair without component disassembly
Safety guidelines
Never exceed rated flex angle — shank breakage is an ejection hazard
Flexing the shank beyond its rated angle under load causes sudden failure. A broken shank can be ejected with significant force. Never force the shank to bend beyond its design limit.
Reduce RPM for flex shaft use
Use 20–30% lower RPM than for a rigid burr of the same head diameter. The flexible shank amplifies any imbalance at high speed, increasing vibration and ejection risk.
Full face shield required
When working inside confined spaces, chip direction is unpredictable. A full face shield is essential — chips can rebound directly back from internal surfaces.
Inspect shank before every use
Check the full shank length for kinks, bends, or flat spots before each use. A kinked shank has a stress concentration point that will break under load — discard immediately.
Support long shanks during use
On 12" and 18" shanks, guide the shank gently with your free hand (gloved) to control flex direction and prevent whipping under load.
Eye & hearing protection always
Wear safety glasses and hearing protection on all operations regardless of duration.
Available lengths & shapes
A series
Cylindrical
Internal flat surfaces, bore wall finishing
Best for flat internal casting surface prep
B series
Cylindrical ball end
Internal pocket corners, blind bore cleanup
Ideal for cleaning up blind-end casting pockets
D series
Ball shape
Concave internal surfaces, internal port work
Most versatile shape for deep internal cavity work
E series
Oval / egg
Curved internal surfaces, transition blending
Best for blending radius transitions inside castings
F series
Tree radius end
Deep internal grooves, weld seams in closed sections
Reaches weld roots inside structural box sections
H series
Flame shape
Internal port work, curved bore surfaces
Top pick for internal manifold and port finishing
Frequently asked questions
How far can the flex shaft bend without damaging the shank?
Our Flex Shaft burrs operate safely at angles up to approximately 15 to 20 degrees of flex under load, depending on shank length. The key rule: never force the shank into a sharp bend under full cutting load — use gentle curves to navigate around obstructions. If you need steeper angles, contact our team at 1-800-645-1679 to discuss your application.
Which shank length should I choose?
Choose based on the depth you actually need. A shorter shank gives more control and less vibration — use 6 inches for depths up to 4 inches, 12 inches for medium-depth work up to 9 inches, and 18 inches only when full depth is genuinely required. Using an 18-inch shank for a 4-inch-deep job significantly reduces control and increases risk.
Are Flex Shaft burrs available in aluma-cut for aluminum work?
Yes. Flex Shaft burrs are available in aluma-cut geometry for internal aluminum casting work and deep bore finishing on non-ferrous components. Particularly popular for reaching deep inside aluminum cylinder heads and intake manifolds where the single-cut geometry prevents chip packing in confined spaces. Contact us at 1-800-645-1679 to confirm availability for your required shape and length.
Why buy from Carbide Burrs Direct
USA-made Flex Shaft burrs — reach where rigid tools cannot
6", 12" and 18" flexible shanks with full solid carbide cutting performance.
3 shank lengths — 6", 12", and 18" for every depth requirement
Double cut & aluma cut available — ferrous and non-ferrous internal work
All major shapes available — cylindrical, ball, oval, tree, flame
Solid carbide head — full cutting power regardless of shank length
Resharpening available — extend the life of your flex shaft burr heads
Fast shipping — same or next business day on all in-stock items
