A bolted attachment having opposite threaded sections between which a shank is provided having at least two shank sections with different diameter located at a length from the threaded section of at least three times the difference between a diameter of a threaded section and a minimum diameter of the shank. At least one conical transition is formed between two adjacent shank sections where the ratio of its length to a difference between a diameter at one end of the transition and a diameter at the opposite end of the transition is of at least 0.85.

A two-piece, one-sided-installation fastener system may have an internally-threaded sleeve having a shank and a sleeve head. The fastener system may include an externally-threaded core bolt having a frangible driving provision and a core bolt head.

A two-piece, one-sided-installation fastener system may have an internally-threaded sleeve having a shank and a sleeve head. The fastener system may include an externally-threaded core bolt having a frangible driving provision and a core bolt head.

Various embodiments include an assembly comprising: a housing; a flange having a first and second flange side; a collar extending into a connector opening of the flange; and a depression running around the assembly opening on the first flange side. The flange has a first assembly opening spaced from the connector opening. The depression includes an inner periphery running laterally along an entire circumference of the first flange side spaced from the assembly opening.

A male screw body comprises a shaft part, a first spiral groove that is formed in a circumferential surface of the shaft part and that is set at an appropriate lead angle and/or lead direction, and a second spiral groove that is set at a lead angle and/or lead direction that is different from the lead angle and/or lead direction of the first spiral groove, wherein the thread angle formed by a pair of inclined surfaces that extend from the apex to the valley of a screw thread that is created as a result of the first spiral groove and the second spiral groove being formed to overlap is established at 61-75. It is thus made possible for a male screw body to have two types of overlapping spiral grooves with different lead angles and/or lead directions to retain high fastening force.

A safety fastener and a safety system are provided. The safety fastener indicates when a fastener is damaged, and the safety system indicates when a safety critical component is damaged. The fastener includes a load bearing body that encloses an inner volume filled with fluid, and a fluid sensor that detects the presence of the fluid within the inner volume. When the fluid sensor detects the fluid, a fluid present state is activated. If the fastener is damaged, fluid may escape from the inner volume, such that the fluid sensor leaves the fluid present state, indicating damage has occurred.

A safety fastener and a safety system are provided. The safety fastener indicates when a fastener is damaged, and the safety system indicates when a safety critical component is damaged. The fastener includes a load bearing body that encloses an inner volume filled with fluid, and a fluid sensor that detects the presence of the fluid within the inner volume. When the fluid sensor detects the fluid, a fluid present state is activated. If the fastener is damaged, fluid may escape from the inner volume, such that the fluid sensor leaves the fluid present state, indicating damage has occurred.

A thermally stabilized fastener system and method is disclosed. The disclosed system/method integrates a fastener (FAS) incorporating a faster retention head (FRH), fastener retention body (FRB), and fastener retention tip (FRT) to couple a mechanical member stack (MMS) in a thermally stabilized fashion using a fastener retention receiver (FRR). The MMS includes a temperature compensating member (TCM), a first retention member (FRM), and an optional second retention member (SRM). The TCM is constructed using a tailored thermal expansion coefficient (TTC) that permits the TCM to compensate for the thermal expansion characteristics of the FAS, FRM, and SRM such that the force applied by the FRH and FRR portions of the FAS to the MMS is tailored to a specific temperature force profile (TFP) over changes in MMS/FAS temperature. The TCM may be selected with a TTC to achieve a uniform TFP over changes in MMS/FAS temperature.

A thermally stabilized fastener system and method is disclosed. The disclosed system/method integrates a fastener (FAS) incorporating a faster retention head (FRH), fastener retention body (FRB), and fastener retention tip (FRT) to couple a mechanical member stack (MMS) in a thermally stabilized fashion using a fastener retention receiver (FRR). The MMS includes a temperature compensating member (TCM), a first retention member (FRM), and an optional second retention member (SRM). The TCM is constructed using a tailored thermal expansion coefficient (TTC) that permits the TCM to compensate for the thermal expansion characteristics of the FAS, FRM, and SRM such that the force applied by the FRH and FRR portions of the FAS to the MMS is tailored to a specific temperature force profile (TFP) over changes in MMS/FAS temperature. The TCM may be selected with a TTC to achieve a uniform TFP over changes in MMS/FAS temperature.

A thermally stabilized fastener system and method is disclosed. The disclosed system/method integrates a fastener (FAS) incorporating a faster retention head (FRH), fastener retention body (FRB), and fastener retention tip (FRT) to couple a mechanical member stack (MMS) in a thermally stabilized fashion using a fastener retention receiver (FRR). The MMS includes a temperature compensating member (TCM), a first retention member (FRM), and an optional second retention member (SRM). The TCM is constructed using a tailored thermal expansion coefficient (TTC) that permits the TCM to compensate for the thermal expansion characteristics of the FAS, FRM, and SRM such that the force applied by the FRH and FRR portions of the FAS to the MMS is tailored to a specific temperature force profile (TFP) over changes in MMS/FAS temperature. The TCM may be selected with a TTC to achieve a uniform TFP over changes in MMS/FAS temperature.