---
product_id: 444834559
title: "MASTERY MART 28 Inch Office Chair Base, Heavy Duty 2400 Lbs, Reinforced Metal Desk Chair Replacement, Universal Gas Cylinder Hole Caster Socket, Matte Black"
brand: "mastery mart"
price: "¥23495"
currency: JPY
in_stock: true
reviews_count: 5
category: "Mastery Mart"
url: https://www.desertcart.jp/products/444834559-mastery-mart-28-inch-office-chair-base-heavy-duty-2400
store_origin: JP
region: Japan
---

# Universal fit for 2" gas cylinders & 7/16" casters 2400 lbs heavy-duty load capacity Reinforced metal with matte black finish MASTERY MART 28 Inch Office Chair Base, Heavy Duty 2400 Lbs, Reinforced Metal Desk Chair Replacement, Universal Gas Cylinder Hole Caster Socket, Matte Black

**Brand:** mastery mart
**Price:** ¥23495
**Availability:** ✅ In Stock

## Summary

> 🪑 Reinvent your throne with rock-solid support and sleek style!

## Quick Answers

- **What is this?** MASTERY MART 28 Inch Office Chair Base, Heavy Duty 2400 Lbs, Reinforced Metal Desk Chair Replacement, Universal Gas Cylinder Hole Caster Socket, Matte Black by mastery mart
- **How much does it cost?** ¥23495 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/444834559-mastery-mart-28-inch-office-chair-base-heavy-duty-2400)

## Best For

- mastery mart enthusiasts

## Why This Product

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

## Key Features

- • **Floor-Friendly Design:** Low center of gravity minimizes tipping and protects your floors from damage.
- • **Sleek Matte Black Finish:** Modern powder-coated surface that resists scratches and elevates your workspace aesthetic.
- • **Cost-Effective Chair Revival:** Replace just the base to save hundreds and extend your favorite chair’s life effortlessly.
- • **Unmatched Strength & Stability:** Supports up to 2400 lbs with premium tubular iron construction for ultimate durability.
- • **Seamless Universal Compatibility:** Fits most office and gaming chairs including Herman Miller with standard gas cylinder & caster sizes.

## Overview

The MASTERY MART 28 Inch Office Chair Base is a heavy-duty, reinforced metal replacement designed to support up to 2400 lbs. Featuring a universal fit for 2" gas cylinders and 7/16" casters, it suits most office and gaming chairs, including premium brands like Herman Miller. Its matte black powder-coated finish offers durability and a modern look, while the low center of gravity ensures stability and floor protection. Easy to install and budget-friendly, this base revives your chair without the cost of a full replacement.

## Description

MASTERY MART 28" Heavy Duty Office Chair Base Replacement Parts, 2400 Lbs, Desk Chair Reinforced Metal Leg with Universal Gas Cylinder Hole and Casters Sockets, Matte Black

Review: Fits Stapes Dexley Chair, brought old chair back to life! - A crack formed in the plastic base of my "Union & Scale Dexley" chair from Staples, as seen in the "BEFORE" pictures. This caused a tilt that made the chair almost unusable, though the rest of the chair was in excellent condition. I was able to remove the old base using a hacksaw, several hours, several bandaids, and lots of sweat. Installing the new base was simple - it only took a few minutes, 5 screws, and installing the old wheels (which fit perfectly). Now instead of spending $180-$400 on a new chair, my old chair is working good as new ("AFTER" picture). I weigh about 330 pounds, I will update this review if the base fails in the future, but it seems pretty sturdy. I want to reiterate how difficult it was to remove the old base. If you have a crack like mine, know that there is a metal ring on the piston that digs into the plastic, basically fusing with the base. No amount of hammering will get it off. You will need to cut it off like I did, though interestingly the base was pushed so far up that I could have just put the new base on the bottom and it would have worked fine (2 bases!). I think if I get a new chair with a plastic base in the future, I will hammer off this one and use it again instead. Plastic bases are trash.
Review: Llevo cerca de medio año y sin problemas - Se ve que estos soportes son soldados a mano, por las malas reseñas que vi yo creo que mejoraron la forma en la que hacen las soldaduras porque se ven mejor hechas cerca de todos los ángulos

## Features

- 🥇【Universal Size】Mastery Mart gaming chair base replacement is suitable for most chairs on the market including Herman miller (office chair, game chair, office chair, executive chair). It supports casters measuring 7/16" x 7/8" (11 mm x 22 mm) and gas cylinders with a 2" (5 cm) diameter.
- 🥇【Premium Craftsmanship】Crafted from premium chrome-plated metal, this heavy-duty base features a sleek matte finish. Its robust tubular iron construction, reinforced with heavy-duty screws, provides superior load-bearing capacity and stability, supporting weights of up to 2400 lbs.
- 🥇【Safety & Floor Protection】Our office chair base replacement prioritizes stability by maintaining a low center of gravity, helping prevent tipping and floor scratches. It not only protects your flooring but also saves you from the cost of buying a new chair.
- 🥇【Budget-Friendly Solution】Replacing just the chair base is a smart and cost-effective solution if your seat is still in good condition. Save money while keeping your favorite chair in use.
- 🥇【100% Satisfaction Guaranteed】Very easy to install and replacement with our simple and clear instruction sheet. If this doesn't fit your chair, you can simply return it.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B09X4MHQP4 |
| Additional Features | Ergonomic |
| Age Range Description | Adult |
| Arm Style | Armless |
| Back Style | Solid Back |
| Best Sellers Rank | #91,288 in Home ( See Top 100 in Home ) #71 in Home Office Furniture Casters |
| Brand | MASTERY MART |
| Brand Name | MASTERY MART |
| Color | Matte Black |
| Colour | Matte Black |
| Customer Reviews | 4.4 out of 5 stars 800 Reviews |
| Fill Material | Foam |
| Finish Types | Powder Coated |
| Frame Material Type | Metal |
| Furniture Base Movement | Glide |
| Furniture Finish | Chrome and Matt Black |
| Included Components | Caster |
| Indoor Outdoor Usage | Indoor |
| Is Foldable | No |
| Item Dimensions D x W x H | 71.1D x 71.1W x 10.2H centimeters |
| Item Weight | 3 Kilograms |
| Item height | 4 inches |
| Item weight | 3 Kilograms |
| Leg Style | wheels |
| Manufacturer | Mastery Mart Co., Limited |
| Material | Metal |
| Material Type | Metal |
| Maximum Weight Recommendation | 1088.62 kg |
| Model Number | MM-BASE-REP-C-BLACK |
| Pattern | Solid |
| Product Care Instructions | Wipe Clean |
| Product dimensions | 71.1D x 71.1W x 10.2H centimeters |
| Reclining Position Count | 1 |
| Recommended Uses For Product | Gaming, Office |
| Room Type | Office |
| Seat Depth | 71.1 centimeters |
| Seat Height | 28 Inches |
| Seat Material | Metal |
| Shape | cat |
| Size | 28D x 28W x 4H in |
| Style Name | Matte Black |
| Surface Recommendation | Hard Floor |
| Tilting | No |
| Unit Count | 1.0 Count |

## Product Details

- **Brand:** MASTERY MART
- **Colour:** Matte Black
- **Material:** Metal
- **Product dimensions:** 71.1D x 71.1W x 10.2H centimeters
- **Size:** 28D x 28W x 4H in

## Images

![MASTERY MART 28 Inch Office Chair Base, Heavy Duty 2400 Lbs, Reinforced Metal Desk Chair Replacement, Universal Gas Cylinder Hole Caster Socket, Matte Black - Image 1](https://m.media-amazon.com/images/I/51HZozdXLlL.jpg)

## Questions & Answers

**Q: Does the bear in the first image come with the purchase, or do i need to buy one separately?**
A: Gotta buy it separately, but still a great product

**Q: Will this fit a serta executive high back office chair with lumbar support ergonomic upholstered swivel gaming friendly design?**
A: Can’t really say as I don’t know the chair. If it has a standard base it should fit without any issues. I used the one we bought for a gaming chair and it worked great.

**Q: Are the wheel inserts metal as well? My chair came with a metal base, but the inserts where the wheels fit into it were plastic and broke.**
A: I believe it's all metal..

**Q: Is the base one piece?**
A: No the base is not one piece.  The base must be assembled.  However, the way it constructed makes it very strong.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Fits Stapes Dexley Chair, brought old chair back to life!
*by T***L on 24 July 2023*

A crack formed in the plastic base of my "Union & Scale Dexley" chair from Staples, as seen in the "BEFORE" pictures. This caused a tilt that made the chair almost unusable, though the rest of the chair was in excellent condition. I was able to remove the old base using a hacksaw, several hours, several bandaids, and lots of sweat. Installing the new base was simple - it only took a few minutes, 5 screws, and installing the old wheels (which fit perfectly). Now instead of spending $180-$400 on a new chair, my old chair is working good as new ("AFTER" picture). I weigh about 330 pounds, I will update this review if the base fails in the future, but it seems pretty sturdy. I want to reiterate how difficult it was to remove the old base. If you have a crack like mine, know that there is a metal ring on the piston that digs into the plastic, basically fusing with the base. No amount of hammering will get it off. You will need to cut it off like I did, though interestingly the base was pushed so far up that I could have just put the new base on the bottom and it would have worked fine (2 bases!). I think if I get a new chair with a plastic base in the future, I will hammer off this one and use it again instead. Plastic bases are trash.

### ⭐⭐⭐⭐⭐ Llevo cerca de medio año y sin problemas
*by D***O on 7 March 2024*

Se ve que estos soportes son soldados a mano, por las malas reseñas que vi yo creo que mejoraron la forma en la que hacen las soldaduras porque se ven mejor hechas cerca de todos los ángulos

### ⭐⭐⭐⭐⭐ Metal Chair Base
*by F***L on 9 June 2025*

Bought as a replacement for the ABS plastic base on my chair. The black metal low profile base comes in a shoebox sized package. Assembly is required. There are 5 spokes, a central Hub, and a cosmetic plastic cover. All parts are individually plastic wrapped to protect the powder coat. Also supplied is a packet of m6 hex bolts and an allen key/hex wrench. There is only one way a spoke will fit on the hub and the spokes are identical. My hub had two drilled holes per spoke but only the one closest to the center had threads to receive the bolt. There is a reasonable friction fit on the spokes so take care to align the the holes for the bolts when sliding the spoke onto the hub as it may take a little bit of force to move it around. Base is exactly the same size and height as the plastic one it replaced. Center opening is a standard 2"/50mm and my gas lift fit perfectly. No wheels were supplied but again the spokes have sockets for a standard 11mm caster and the wheels from the original base fit perfectly. Assembly was straightforward and took about 15 minutes. It was delivered at 12.30 and I was sat in my chair writing this review by 1pm. Reassembling the Chair was straightforward (!! remember to put the plastic cover on the gas strut first!)! Probably the most difficult bit was pulling the wheels off the old base.(firm grip and steady pull while twisting) My immediate impression is that it feels solid and sturdy. It seems well made with clean looking welds. I'm a big fella and use my chair daily. If anything goes wrong I'll be back here to tell you about it. Tip. Check on the hex bolts after a week or so, and regularly after that as they will almost certainly loosen over time. Tape the allen key to the bottom of the chair so it is handy if you need it.

## Frequently Bought Together

- MASTERY MART 28" Heavy Duty Office Chair Base Replacement Parts, 2500 Lbs, Desk Chair Reinforced Metal Leg with Universal Gas Cylinder Hole and Casters Sockets, Matte Black
- Mastery Mart Office Chair Caster Wheels for Hardwood Floors, Heavy Duty and Quiet Smooth Rollerblade Wheels for Office Chair, Universal Size (11x22mm), Suitable for Most Chairs
- MASTERY MART Office Chair Gas Lift Cylinder Replacement, 4" Travel Length, Heavy Duty 450 lbs, Hydraulic Pneumatic Shock Piston, Universal Size Fits Most Office Chairs, Class 4, Matte Black

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-03-16*