{TAIL ~ An Nb—Ti—Co alloy} having both good hydrogen permeability and good hydrogen embrittlement resistance comprises one of Fe, Cu or {HEAD ~ Mn} as a fourth element, incorporating from 1 to 14 mol % 
{ TAIL ~ An Nb — Ti — Co alloy } having both good hydrogen permeability and good hydrogen embrittlement resistance comprises one of Fe , Cu or { HEAD ~ Mn } as a fourth element , incorporating from 1 to 14 mol %
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH