Bosch GWS8-45-RT: problems, parts and running costs

Checked: 2026-10-17

Summary

A factory-reconditioned Bosch GWS8-45 120 V, 7.5 A, 4-1/2-inch corded angle grinder with a fixed 11,000 rpm motor and a lock-on slide switch. It is a grinding tool, not a cut-off tool: Bosch’s manual does not approve Type 41/1A metal cutting or concrete/masonry cutting on this model. Running costs are grinding wheels, electricity and occasional brush or bearing service, and the main ownership risk is the unknown condition of a reconditioned unit’s brushes, bearings and switch.

Common problems and fixes

Lock-on slide switch disengaging under load — a November 2016 buyer of the new GWS8-45 reported the lock-on switch disengaging during work; Bosch customer service acknowledged the complaint and no recall or repair bulletin was found. Test on/off and lock-off before use under load. Frequency is not established. [6][12]
Gearhead heating abnormally — a May 2023 buyer said the gear-cover area heated quickly on first use; Bosch replied the heating was not normal and offered an evaluation. Stop, unplug and seek service if the gearbox is abnormally hot, smells burnt or sounds harsh. [6]
Brush wear stops the tool (Service Minder) — the Service Minder carbon brushes stop the tool when maintenance is due; the manual recommends inspecting brushes every 2–6 months and replacing them with genuine matched parts, relubricating gears at each change. On a reconditioned unit the remaining brush life is unknown from the SKU. [2][4][11]
Bearings, switch and cord wear at repair-economics scale — a switch is $24.55, a power cord $19.56, an armature $35.06 and bearings start at $6.55 before labor; one electrical part plus service can exceed the tool’s price. Bosch recommends bearing replacement by a service center at about 300–400 operating hours or every second brush change. [4][7][11]
No approved cut-off use — Bosch’s manual marks Type 41/1A metal cutting, concrete/masonry cutting and Type 1/11 grinding as not supported; a June 2026 Home Depot buyer returned the tool after finding no approved cutting guard. Do not use cut-off discs on this model. [4][5][6]
Reconditioned condition is not documented per unit — Acme’s package lists the grinder, guard, 5/8-inch clamping flange, round nut, wrench, handle and manual and does not list a consumable grinding wheel; no per-unit checklist says which parts were replaced or inspected. Inspect the guard, fasteners, switch, cord, spindle, wobble and sparking while the return window is open. [1][8]

Parts and consumables

Carbon brush set, Bosch 1619P02892 — $17.20 at eReplacementParts on the 3601C88118 model page; another listing showed $15.23 and a closely related type 3601C8811B catalog suggests $11.62. Inspect every 2–6 months; replace when worn or when Service Minder requires service. [4][7][11][16]
On/off switch, Bosch 1607200146 — $24.55 at eReplacementParts; replace on fault, no scheduled interval. [11]
US power cord, Bosch 2604460122 — $19.56 at eReplacementParts; replace promptly if frayed or crushed, no fixed interval. [4][11]
Type 27 protective wheel guard, Bosch 1600A00XU6 — $21.96 at eReplacementParts; replace if bent, cracked or no longer locks. This is a grinding guard, not a cutting certification. [4][11]
Grinding backing/clamping flange, Bosch 1605703140 — $17.20 at eReplacementParts; round lock nut Bosch 3603340503 $21.96; replace only if damaged or lost. [4][11]
Auxiliary handle, Bosch 2828320003 — $5.55; wrench Bosch 1619P08927 $9.76; replace on loss or damage. [1][11]
Type 27 metal grinding wheel (consumable) — Home Depot advertised the Diablo DBD045250701F, 4-1/2-inch × 1/4-inch × 7/8-inch, at $5.47 each; a three-pack DBX045250703P appeared at $11.47, about $3.82 per wheel. Replace when worn or chipped. [4][15]

Yearly running cost

There is no battery, charger or subscription. The principal costs are grinding wheels, electricity and occasional brush or bearing service. Illustrative electricity: the nameplate is 120 V at 7.5 A, about 900 VA of apparent power; assuming 0.75 kW of real draw, 30 minutes a week for 52 weeks at $0.20/kWh gives 19.5 kWh and $3.90 a year. One $5.47 Diablo Type 27 wheel a month adds $65.64 a year, for about $69.54 a year in this example. A $17.20 brush set brings a replacement year to about $86.74. This excludes labor, shipping, personal protective equipment and repairs. [2][4][15]

When it is a good buy

Observed October 2026: Acme Tools’ indexed listing showed the GWS8-45-RT at $49.00, marked down from $65.00, with its usual $6.49 shipping on orders under $199; CPO Outlets listed the same reconditioned tool between $49.99 and $52.99; a new GWS8-45 was $82.98 at Home Depot after an earlier $69 promotional price. At $40 or less renewed with genuine Bosch coverage it is a strong buy for approved Type 27 grinding; $41–50 is good when the job is grinding rather than cutting, so budget a disc if one is missing; $51–60 is less compelling, so compare a new unit at a $69 sale; at $61 or more wait for a discounted new GWS8-45 or pick a model whose manual approves your actual task. Two named alternatives: a new Makita 9557NB at $99 (7.5 A, rotatable gear housing) and a Makita 9557PB paddle-switch at $109 — better if you want new condition or dislike the lock-on slide, but check each one’s guard and application approvals before any cut-off work. [1][3][5][9][10][13][14][15]