Extended shank F Series tree radius end – deep V-groove & weld root at reach
The Extended Shank F Series tree shape with radius end puts the tapered groove-access geometry on a 6-inch shank — reaching weld roots inside box sections, deep structural V-grooves, narrow recess areas, and internal channel grooves that standard shank tools cannot access from the grinder entry position. The radius tip prevents gouging at the groove base even at full 6-inch depth.
SF
series code
6"
shank length
USA
manufactured
Key features & benefits
6-inch extended reach shank
Extends tapered tree geometry to 6 inches from the collet — reaching deep V-grooves, weld roots inside structural sections, and narrow recesses that standard shanks cannot access.
Tapered body + radius tip at depth
Tapered sides access narrow deep grooves and channels at extended reach; radius tip prevents gouging at the groove base when working at full 6-inch depth.
Solid tungsten carbide head
USA-manufactured solid carbide — maintains the tapered profile and radius tip integrity through deep groove and weld root work at extended reach.
Deep weld root prep at reach
Cleans weld roots inside box sections, deep pipe joints, and structural weld joints where back-gouge and root cleaning is required but the grinder body blocks standard shank access.
Double cut & aluma-cut
Double cut for steel, cast iron, and stainless deep groove and root work. Aluma-cut for aluminum and non-ferrous deep channel and recess work at extended reach.
Wholesale direct pricing
Factory-direct from our USA facility — extended shank groove and weld root specialist at competitive rates.
Materials & applications
Material
Deep-reach applications
Why Extended Shank F Series
Structural steel
deep weld root cleaningbox section internal V-groovedeep back-gouge prep
6" reach accesses weld roots inside structural sections standard shanks cannot enter
Steel pipe & tube
long pipe internal root prepdeep pipe joint groove work
Tapered tip reaches deep pipe weld roots without grinder body contact at entry
Cast iron
deep casting narrow pocketinternal channel groove
Extended taper accesses deep narrow casting internal channels at full reach
Aluminum
deep aluminum channel workconfined non-ferrous groove
Aluma-cut extended F Series reaches deep aluminum groove areas without packing
Stainless steel
deep pipe weld root prepinternal seam groove access
6" taper reach cleans stainless weld roots in deep pipe sections
Advantages vs other cut types
Extended Shank F Series
vs
Standard Shank F Series
Reaches weld roots 6" inside structural sections
reach
Grinder body blocks access to deep internal roots
Deep box section & pipe internal groove work
confined
Cannot reach deep internal grooves in closed sections
In-situ weld root prep without disassembly
in-situ
Disassembly required for deep weld root access
Reduce RPM — no lateral force on long shank
rpm
Full RPM range, standard pressure rules apply
Same tapered body + radius tip geometry at depth
geometry
Same tapered body + radius tip geometry
Who should use Extended Shank F Series Tree Shape Radius End burrs
Structural welders & fabricators
Deep weld root cleaning & V-groove work inside box sections & frames
Pipe welders
Long pipe internal weld root prep & deep joint groove access
Maintenance engineers
In-situ deep groove & weld root access on assembled structures
Foundry workers
Deep internal casting narrow channel & groove cleanup at reach
Automotive fabricators
Chassis & frame interior deep groove & weld root work
Safety guidelines
Reduce RPM 20–30% and never force the tip into a tight groove at depth
At 6-inch extended reach, forcing the taper tip into a groove narrower than the tip diameter causes the burr to bind and the long shank to flex violently. Reduce RPM by 20 to 30 percent and always confirm the groove width is larger than the tip before entering. Work with light, consistent axial pressure only.
Keep shank clear of section walls during deep groove work
When working inside box sections and structural cavities, always keep the extended shank clear of the section walls during operation. Shank contact with the wall creates a lateral bending load that fatigues the shank rapidly and can cause sudden shank failure at depth.
Full face shield required
Deep groove and weld root work inside structural sections ejects chips in concentrated streams toward the section entry. A full face shield is mandatory for all extended shank F Series operations.
Inspect shank before every use
Inspect the full 6-inch shank for cracks, bends, or surface marks before every use. Any damage is cause to discard immediately — shank failure at depth inside a structural section is extremely dangerous.
Eye & hearing protection always
Wear safety glasses and hearing protection on all extended shank operations regardless of duration or material.
Clamp workpiece securely
Secure all workpieces before deep groove and weld root work. A shifting workpiece at 6-inch depth can trap the shank inside the section or groove.
How to choose the right shape
SF-1 XS
1/4" x 1/2" / 6" shank
Narrow deep weld root, fine groove work at reach
Best for deep narrow weld root cleaning at 6" reach
SF-3 XS
3/8" x 3/4" / 6" shank
Medium deep V-groove, structural joint root at reach
Most popular extended shank F Series for structural work
SF-5 XS
1/2" x 1" / 6" shank
Standard deep groove work, wide recess at extended reach
Best all-around extended shank tree burr for deep groove
SF-7 XS
5/8" x 1-1/4" / 6" shank
Heavy deep groove, large structural back-gouge at reach
Use for wide V-groove prep deep inside large sections
SF-1 XS Aluma
1/4" aluma-cut / 6" shank
Deep aluminum narrow groove & channel work at reach
For deep aluminum section internal groove access
SF-5 XS DC
1/2" double cut / 6" shank
Standard deep steel V-groove & structural root work
Most-used size for deep structural steel groove & root work
Frequently asked questions
Can the extended shank F Series clean weld roots inside welded box sections?
Yes — this is the primary application for the extended shank F Series tree radius end. Weld roots inside box sections and RHS tubing are a common inspection failure point in structural steel work, and re-cleaning or blending these roots after welding is frequently required without disassembling the structure. The 6-inch shank puts the tapered radius tip at the weld root inside the section while the grinder body remains outside. Work in short controlled strokes along the root line, keeping the shank clear of the section walls. Use double-cut for steel; aluma-cut for aluminum sections.
Why does the F Series use a radius end rather than a pointed end for deep groove work?
At 6-inch extended reach inside a deep groove, a pointed tip (G Series) is significantly more vulnerable to breakage than a radius tip. The longer the shank, the more any vibration or slight tool path deviation concentrates force at the tip. The radius end of the F Series provides a more forgiving tip geometry at depth — it can make contact with the groove base without the immediate chip-off risk that a pointed tip faces at extended reach. For deep groove and weld root work where precision is important but tip fragility is a risk, the F Series radius end is the safer extended shank choice. Use the G Series extended shank only when the groove geometry specifically requires a pointed tip and you can maintain excellent axial control.
What RPM should I run the extended shank F Series at for deep V-groove work?
Reduce RPM by 20 to 30 percent compared to the same SF head size in standard shank. For example, if you normally run a 1/2" SF-5 standard shank at 25,000 to 30,000 RPM, run the extended shank equivalent at 18,000 to 22,000 RPM. The longer the shank, the more critical the RPM reduction — any vibration at extended reach inside a deep groove amplifies significantly compared to surface work. If you feel chatter at a given RPM, reduce further until the cut is smooth and well-controlled. Contact us at 1-800-645-1679 for specific RPM guidance on extended shank F Series sizes for your application.
Why buy from Carbide Burrs Direct
USA-made Extended Shank F Series — deep weld root & V-groove access at full reach
Tapered tip reaches deep structural roots & grooves standard shanks cannot access — factory direct.
SF-1 through SF-7 extended shank in stock — narrow root to heavy groove work
Double cut & aluma-cut — steel & aluminum deep groove work covered
Standard 1/4" shank diameter — fits all die grinders without adapter
Professional resharpening — restore taper profile & radius tip for reuse
