Even the best tool can fail; always use a continuity tester after crimping to verify the pinout. If you'd like to narrow this down, let me know: Are you wiring an entire house or just repairing one cable ?
Rubberized grips prevent hand fatigue during large installations. 💡 Pro Tips for a Perfect Connection best buy rj45 crimp tool
Keep the pairs twisted as close to the connector as possible to reduce interference (crosstalk). Even the best tool can fail; always use