Applying lubricant to a threaded fastener affects the torque-tension relationship by:

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Multiple Choice

Applying lubricant to a threaded fastener affects the torque-tension relationship by:

Lubricant reduces friction in the threads and under the bolt head, so when you apply torque, less energy is spent rubbing against surfaces and more is used to stretch the bolt and create clamping force. In the torque–tension relationship, lowering friction (the torque coefficient) means a given torque produces more axial tension. Since diameter is fixed for a given bolt, reducing friction yields a higher clamp load for the same torque. So, using lubricant makes the bolt clamp harder, i.e., it increases the clamp load at the same torque value.

Lubricant reduces friction in the threads and under the bolt head, so when you apply torque, less energy is spent rubbing against surfaces and more is used to stretch the bolt and create clamping force. In the torque–tension relationship, lowering friction (the torque coefficient) means a given torque produces more axial tension. Since diameter is fixed for a given bolt, reducing friction yields a higher clamp load for the same torque. So, using lubricant makes the bolt clamp harder, i.e., it increases the clamp load at the same torque value.

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