---
product_id: 735082604
title: "FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain"
brand: "focmkeas"
price: "฿1387"
currency: THB
in_stock: true
reviews_count: 4
category: "Focmkeas"
url: https://www.desertcart.co.th/products/735082604-focmkeas-21-tooth-roller-chain-sprocket-b-type-hardened-teeth
store_origin: TH
region: Thailand
---

# Includes 2 set screws for secure shaft fit 21 hardened teeth for precision torque Black oxide coated corrosion resistance FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain

**Brand:** focmkeas
**Price:** ฿1387
**Availability:** ✅ In Stock

## Summary

> ⚙️ Lock in power, unlock performance — the sprocket that means business!

## Quick Answers

- **What is this?** FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain by focmkeas
- **How much does it cost?** ฿1387 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.th](https://www.desertcart.co.th/products/735082604-focmkeas-21-tooth-roller-chain-sprocket-b-type-hardened-teeth)

## Best For

- focmkeas enthusiasts

## Why This Product

- Trusted focmkeas brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Secure Shaft Locking:** Equipped with dual set screws and Type B hub design to prevent slipping and ensure stable operation.
- • **Compact & Lightweight:** At just 75g with a 12mm bore, it fits seamlessly into tight mechanical assemblies without adding bulk.
- • **Precision Engineered 21 Teeth:** Optimized for smooth, reliable power transmission with high-frequency quenched hardness.
- • **Durable C45 Carbon Steel Build:** Crafted from premium carbon steel with black oxide finish to resist wear and corrosion in harsh environments.
- • **Versatile Industrial Compatibility:** Perfect for milling, drilling, and machinery requiring robust single-strand chain drive solutions.

## Overview

The FOCMKEAS 21 Tooth Roller Chain Sprocket is a high-precision, single-strand sprocket made from hardened C45 carbon steel with a black oxide coating for enhanced durability and corrosion resistance. Featuring a 1/4-inch pitch and 12mm bore, it includes two set screws and a Type B hub to ensure secure shaft mounting. Ideal for industrial power transmission in demanding environments, this sprocket delivers reliable torque support and long service life.

## Description

Chain Sprockets are normally mounted in a fixed position on a fixed shaft. Keyway with 2pcs Set Screws at 90 degrees. The shaft can be fixed well, which is convenient to use. The chain sprocket should not rotate at a greater speed than is allowable for drive sprockets of the same size. Every roller chain sprocket comes with strong teeth that can latch onto the chain. It is suggested that chain sprockets have at least three teeth in mesh with the chain.

Review: Great fit!
Review: Doesn't stay clamped to axle.

## Features

- 【Size&Package】1/4" pitch, 21 teeth, 12mm round bore, more size refer to pics. Package include:1 x Chain Sprocket, 2 x Set Screws.
- 【Material】Made by c45 carbon steel, the tooth part high frequency quenching heat treatment, high hardness, wear resistance, long service life, easy to use. Fully black oxide coated, corrosion resistance.
- 【Feature】Single strand sprocket with one set of teeth around the circumference for applications where a single chain can support the torque and load.
- 【Type B】Type B sprocket with a hub project on one side to accommodate various types of bushings to help prevent sprocket from slipping on the shaft.
- 【Application】Widely used in various industrial scenarios, suitable for power transmission in harsh environments.such as milling machine, drilling machine or other machinery transmission occasions.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Manufacturer | FOCMKEAS |
| Part number | 21T/12mm Bore |
| Item Weight | 75 g |
| Package Dimensions | 12 x 9.3 x 1.7 cm; 75 g |
| Item model number | 21T/12mm Bore |
| Size | 21T/12mm Bore |
| Colour | Black |
| Material | Carbon Steel |
| Item Package Quantity | 1 |
| Teeth Per Inch | 0.25 inches |
| Special Features | single_strand, triple_strand |
| Batteries included? | No |
| Batteries Required? | No |

## Images

![FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain - Image 1](https://m.media-amazon.com/images/I/6157EsZmgBL.jpg)
![FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain - Image 2](https://m.media-amazon.com/images/I/61Ewp0l+4QL.jpg)
![FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain - Image 3](https://m.media-amazon.com/images/I/71BmZivgfhL.jpg)
![FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain - Image 4](https://m.media-amazon.com/images/I/71e-75IzKKL.jpg)
![FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain - Image 5](https://m.media-amazon.com/images/I/71sPhFw6EEL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great fit!
*by N***N on 5 February 2025*



### ⭐⭐ Doesn't stay clamped to axle.
*by R***W on 12 February 2025*



### ⭐⭐⭐⭐⭐ Fit great
*by A***R on 18 June 2024*



## Frequently Bought Together

- FOCMKEAS 21 Tooth Roller Chain Sprocket B Type Hardened Teeth, 25 Chain Sigle Strand 1/4-Inch Pitch, 12mm Bore Black Oxide C45 Carbon Steel with Fasten Screws for 04C Chain
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*Product available on Desertcart Thailand*
*Store origin: TH*
*Last updated: 2026-01-27*