The GMX GM-TH003 universal heavy-duty fixed line trimmer head is designed for demanding grass, weed, and brush-cutting applications where simple line replacement and dependable operation are preferred over an internal bump-feed mechanism. The head uses the popular ECHO SRM-pattern M10 x 1.25 left-hand female mounting thread: 10 mm nominal threaded center diameter, 1.25 mm pitch, and left-hand direction. Two pre-cut line sections install directly through reinforced metal eyelets, helping reduce spool tangles, spring failures, and line-feeding interruptions. The head accepts heavy-duty 0.095-inch through 0.130-inch line and is supplied with dark green 0.105-inch square line. Fitment must be confirmed by thread diameter, pitch, direction, counterbore clearance, gearbox clearance, and guard clearance.
Key Features
- Fixed-line design eliminates internal spool, spring, and bump-feed components
- Quick line replacement using two pre-cut line sections through reinforced eyelets
- Accepts heavy-duty 0.095-inch, 0.105-inch, and up to 0.130-inch pre-cut trimmer line
- M10 x 1.25 LH female center thread matched to popular ECHO SRM straight-shaft applications
- Low-profile fixed-line body helps reduce tangling and simplifies field servicing
- Reinforced metal eyelets and high-impact matte black housing for heavy-duty use
- Designed for thick grass, heavy weeds, fence lines, edging, and professional landscape maintenance
Mounting / Compatible Head Specifications
| Reference Type |
Compatible Specification / Application |
| Mounting Interface |
ECHO SRM-pattern M10 x 1.25 left-hand female thread |
| Rotation |
Counterclockwise cutting-head rotation |
| Primary ECHO Models |
SRM-225, SRM-225i, SRM-225U, SRM-230, SRM-2320T, SRM-2620, SRM-2620T, SRM-2620U |
| Shindaiwa / Conditional Fit |
Shindaiwa T225, T235, T262, T262X, C262; selected Husqvarna, RedMax, Makita, Maruyama and other M10 x 1.25 LH straight-shaft units after verification |
| Fitment Check |
Verify thread diameter, pitch, direction, counterbore depth, gearbox and guard clearance |
Fits Brands
Fits ECHO straight-shaft SRM trimmers using the M10 x 1.25 LH pattern and the listed Shindaiwa models. Other brands fit only when the thread, rotation, counterbore, gearbox, and guard clearances match.
Fits Models / Trimmer Families
ECHO: SRM-225, SRM-225i, SRM-225U, SRM-230, SRM-2320T, SRM-2620, SRM-2620T, SRM-2620U. Shindaiwa: T225, T235, T262, T262X, C262. Conditional fit for selected Husqvarna, RedMax, Makita, Maruyama, and other straight-shaft units only when the mounting interface is M10 x 1.25 LH. Not for ECHO GT curved-shaft units or clockwise-thread installations.
Package Contents
1 x GMX GM-TH003 heavy-duty fixed line trimmer head with two pre-cut dark green 0.105-inch square line sections
Listing Information
| Product Title |
GMX Heavy-Duty Fixed Line Trimmer Head, ECHO SRM Pattern, M10 x 1.25 LH |
| URL Handle |
gm-th003-echo-srm-pattern-heavy-duty-fixed-line-trimmer-head |
| Meta Title |
ECHO SRM-Pattern Fixed Line Trimmer Head M10 x 1.25 LH | GMX |
| Meta Description |
GMX heavy-duty fixed line trimmer head with ECHO SRM-pattern M10 x 1.25 LH mounting, matte black housing, metal eyelets and dark green line. |
| Search Tags |
GM-TH003, GMX, fixed line trimmer head, ECHO SRM trimmer head, SRM-225 replacement head, M10 x 1.25 LH, heavy duty, square line, Shindaiwa |
Installation and Safety Notes
- Verify M10 x 1.25 LH thread, counterclockwise rotation, counterbore depth, gearbox clearance, and guard clearance before installation. ECHO GT curved-shaft models are not included.
- Stop the engine and disconnect the spark plug before service. Tighten securely, wear required PPE, and inspect the housing, eyelets, line, and mounting threads before each use. Replace both line sections evenly to maintain balance.
