Description Thread Repair Kit for Glow Plugs - M8 x 1.0 Taps and coil inserts for repairing M8 glow plug threads. 5 x 12mm Deep Inserts with black phosphate finish. Essential kit that solves common problems on diesel engine alloy cylinder heads. Rectifies cross-threading and over tightening. This kit ensures a straight thread and the new insert provides an efficient fit. Insert material is Carbon Steel.
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