1) Subminiature fuses are heat sensitive and not mechanically rugged.  Use special handling and soldering for these parts.  These fuses are particularly susceptible to internal fracture during lead bending.  If lead forming is required, always support the lead between the endcap and desired bend area prior to bending.  Never bend the lead while grasping the fuse body.

2) FM04 and FM08 fuses rated at 1/2 Ampere or less require special application considerations.  These fuses use a different material for the fuse element than the higher amperage devices.  Due to the difference in thermal conductivity, the lower amperage devices rely heavily on air conduction as a means of heat transfer.  The potential loss of the atmosphere within the fuse package (due to the loss of hermeticity during prolonged exposure to the space environment) will have a significant impact on the element's ability to transfer heat.  This situation may lead to over heating of the element.  To compound the concerns, at elevated temperatures the thermal conductivity of the element for the lower amperage devices changes drastically which can lead to sudden thermal changes.  These thermal changes may lead to premature thermal and/or mechanical fatigue failure of the fuse element.  Consult a parts engineering specialist for further details on this phenomenon.