K20 Micro-Grain Rod Stock for Toolmaking

Carbitool Carbide Rod Blanks give toolmakers, engineering workshops, cutter manufacturers & specialist maintenance teams cylindrical carbide stock for producing or modifying precision tooling. Carbitool's CRR unground rods are documented as ISO K20 SMG micro-grain carbide in 330mm lengths, with a broad selection of imperial diameters for buyers who need to begin with raw carbide material rather than a finished cutter.

Buyers sourcing other carbide forms can compare Carbitool Carbides, while workshops moving from raw stock to cutting-tool manufacture can explore Cutting Tools for the wider cutting-tool category.

These products should not be confused with finished router bits, drills or carbide burs. A carbide rod blank is material stock. Diameter, length, grade & whether the rod is supplied ground or unground are therefore the important selection criteria.

What Are Carbitool Carbide Rod Blanks?

Carbitool Carbide Rod Blanks are cylindrical carbide material supplied for appropriate toolmaking & specialist manufacturing requirements.

Carbitool's carbide-material catalogue separates its cylindrical rods into two principal families:

• CRR – unground carbide rods

• CRRG – precision-ground carbide rods

The Industrial Shed Carbides Rod Blanks collection currently centres on CRR unground rods carrying the K20 SMG designation.

Carbitool documents its cylindrical rods at 330mm long & identifies the material as ISO K20 SMG micro-grain carbide.

This distinction matters because an unground rod is not dimensionally equivalent to a precision-ground finished shank or cutter. It is stock intended for subsequent processing appropriate to the tooling application.

Understanding Carbitool CRR Rod Sizes

The Carbitool CRR range covers numerous imperial diameters. Examples include:

Carbitool's broader CRR catalogue extends beyond these examples, so buyers should select the exact rod diameter required by the intended downstream process.

Why Choose Carbitool Carbide Rod Blanks?

Raw carbide stock serves a very different buying requirement from ready-to-use cutting tools.

A toolmaker purchasing a rod blank needs enough material to manufacture the required geometry while accounting for the subsequent production process. The correct starting diameter can therefore be more important than familiar finished-tool specifications such as flute count or cutting length.

K20 SMG Material Is Clearly Identified

Carbitool specifies ISO K20 SMG micro-grain carbide for its documented cylindrical rod range.

That grade identification gives professional buyers a defined material reference rather than requiring them to assume that every carbide product sold under the Carbitool name has identical composition or characteristics.

The K20 SMG designation should remain attached to purchasing & workshop records when the grade forms part of the tooling specification.

Unground Rods Provide Material for Subsequent Processing

The CRR products are explicitly identified as unground rods.

This is an important purchasing distinction.

A buyer who requires raw cylindrical stock for subsequent toolmaking has a different requirement from one who needs a precision-ground rod with a specified finished tolerance.

Carbitool separately documents CRRG ground rods, confirming that ground & unground stock should not be treated as equivalent product forms.

A Broad Diameter Range Supports Different Tooling Requirements

Carbitool's CRR family spans small through substantially larger rod diameters.

That breadth allows the starting stock to be selected according to the dimensions of the intended component rather than forcing a very different diameter into the production process.

Accurate measurement remains important when identifying existing tooling or establishing the required blank size. Calipers (Digital / Manual) provide a relevant workshop option for dimensional checking.

Common Applications

Cutting-Tool Manufacture

Carbide rod stock is closely associated with round cutting-tool manufacture.

The rod provides the starting material from which the required tool geometry can be produced using appropriate specialist equipment & processes.

The finished tool might require flutes, cutting edges, relief geometry, a defined shank or other features, but those details are created downstream. The CRR product itself remains an unground carbide blank.

Custom Tooling

Standard finished cutters do not cover every machining requirement.

Specialist workshops may require a tool with a particular diameter, reach or geometry that is not available as an off-the-shelf cutter.

Carbide rod blanks provide raw cylindrical stock for appropriate custom-tool manufacturing processes where the selected grade & dimensions meet the design requirements.

Toolmaking & Engineering Workshops

For a toolmaking operation, physical stock dimensions are a purchasing decision rather than an incidental specification.

The required finished component, machining allowance & production process should determine the starting rod diameter.

Where workshop layouts, reference dimensions or component checks are required, Measuring & Layout Tools provide another useful supporting category.

Specialist Replacement Tool Production

Older machinery, dedicated production equipment or specialised manufacturing processes can sometimes require tooling that is difficult to replace directly from standard finished ranges.

Where manufacture of a replacement tool is appropriate, carbide rod stock can provide the starting material.

The existing component should be properly specified before raw stock is ordered. Copying only one visible dimension from an old tool can overlook other design requirements.

Prototype Tool Development

Tool development frequently begins with dimensions & geometry that need to be proven before a final production specification is established.

A carbide blank can serve as starting stock for suitably equipped specialists developing a custom cutter or tooling concept.

The manufacturing process, carbide grade & blank dimensions should all be considered before the material is committed.

Product Selection Guide

Establish the Required Finished Tool First

Raw material selection should work backwards from the component being manufactured.

Determine the required finished diameter, geometry, usable length & manufacturing process before choosing a rod.

This prevents the starting stock from being selected simply because a familiar imperial diameter is available.

Select the Correct Rod Diameter

Carbitool's CRR range includes closely spaced imperial sizes.

For example, 13/64", 15/64", 17/64", 19/64", 21/64" & 23/64" rods are separate products.

That progression gives toolmakers useful size options, but it also makes precise ordering important.

Use the complete CRR part number rather than relying on a description such as “small carbide rod”.

Confirm the Carbide Grade

The CRR cylindrical rods documented by Carbitool carry the K20 SMG designation.

Where the tooling design specifies a particular material grade, confirm the exact product reference before purchase.

Do not assume another carbide blank, strip, insert or finished cutter has the same grade merely because it is also manufactured from carbide.

Distinguish Unground From Ground Rod

The Industrial Shed collection includes CRR products described as Unground Rod.

Carbitool's catalogue separately identifies CRRG rods as ground products, documenting the ground family to an h6 tolerance with a polished finish.

A buyer requiring ground stock should therefore not substitute an unground CRR rod without accounting for the different material condition.

Confirm the Required Length

Carbitool documents its standard CRR & CRRG cylindrical rods at 330mm length.

The manufacturer also states that ground & unground rods can be cut to length on application.

Where the manufacturing process requires a particular blank length, establish that requirement before material preparation begins.

Allow for the Manufacturing Process

A nominal raw-stock diameter is not automatically the finished tool diameter.

Subsequent grinding or other specialist processing can remove material.

The person responsible for producing the finished tool should determine the appropriate starting stock rather than selecting a blank from the final diameter alone.

Expert Tips

Keep the Grade Visible After Material Is Separated

Once a rod is removed from labelled stock or divided for manufacturing, its material identity can become harder to establish.

Maintain traceable identification for the K20 SMG stock throughout storage & production where grade verification matters.

This is particularly useful in workshops holding more than one carbide form or specification.

Record Both Imperial & Metric Diameters

Carbitool provides imperial rod dimensions together with metric equivalents.

Recording both can reduce ambiguity where drawings, measuring equipment & workshop staff use different dimensional conventions.

For example, CRR48 is identified as 3/4" or 19.05mm, while CRR32 is 1/2" or 12.70mm.

Separate Unground Stock From Finished Tooling

An unground carbide rod can resemble the cylindrical body or shank of finished tooling, particularly when several carbide products are stored together.

Keep raw rod blanks clearly separated from completed cutters & other carbide components.

Tool Storage provides a relevant supporting category for workshops organising specialist stock, tooling & precision components.

Avoid Treating Product-Card Router Copy as the Material Specification

The live Industrial Shed product cards currently describe several CRR unground rods with generic router-bit wording.

That wording does not accurately describe the product form.

The Carbitool carbide-material specification should be used when identifying these products: they are K20 SMG cylindrical carbide rod blanks, not finished router bits.

Use the Manufacturer Part Number in Purchasing Records

Descriptions such as “3/4 carbide bar” can become ambiguous when several material grades or stock conditions exist.

A record such as CRR48 K20 SMG – 3/4" unground rod preserves the manufacturer reference, nominal diameter, material designation & product form in one line.

Keep Material Preparation Separate From Cutter Selection

A carbide rod blank is not selected using the same criteria as a router bit, bur or drill.

Finished cutters are evaluated by cutting geometry, machine interface & application. Raw rods are first evaluated by material form, grade, diameter, length & the requirements of the downstream manufacturing process.

Industrial Shed's The Black Print: Best Tool Brands Industrial Shed Rundown provides broader context for professional workshop tooling selection.

Maintain Workshop Knowledge Around Specialist Materials

Raw carbide stock often sits within a specialised manufacturing workflow where process knowledge is as important as the material itself.

Documenting stock references, tooling drawings & proven manufacturing information helps prevent that knowledge from existing only in one person's memory.

Whispers & Wisdom: We Are Losing the Art of the Master Tradesperson examines the wider importance of retaining practical trade knowledge, while A tool is not just a tool. It’s a promise. provides further perspective on professional tooling decisions.