Recently, biometric template protection has received great attention from the research community due to the security and privacy concerns for biometric template. Although a number of biometric template protection methods have been reported, it is still a challenging task to devise a scheme which satisfies all of the four template protection criteria namely diversity, revocability, non-invertibility and performance. In this paper, a method is proposed to generate a revocable fingerprint template in terms of bit-string from a set of minutiae points via a polar grid based 3-tuple quantization technique. Two merits of the proposed method are outlined, namely alignment-free and performance. Four publicly available benchmark datasets: FVC2002 DB1, DB2 and FVC2004 DB1, DB2 are used to evaluate the performance of the proposed method. Besides, the diversity, revocability, non-invertibility criteria are also analyzed.