T2.5节距：2.5MM
规格	齿数	节径 D	外径 Do	档边直径 Df	档边内径 db	档边厚度 h
18-T2.5	18	14.32	13.79	18	11	1
19-T2.5	19	15.12	14.59	18	12.5	1
20-T2.5	20	15.92	15.39	18	12.5	1
21-T2.5	21	16.71	16.18	18	12.5	1
22-T2.5	22	17.51	16.98	22	13	1
23-T2.5	23	18.3	17.77	22	13	1
24-T2.5	24	19.1	18.57	22	13	1
25-T2.5	25	19.89	19.36	22	13	1
26-T2.5	26	20.69	20.16	25	15	1
27-T2.5	27	21.49	20.96	25	15	1
28-T2.5	28	22.28	21.75	25	15	1
29-T2.5	29	23.08	22.55	25	15	1
30-T2.5	30	23.87	23.34	29	21	1
32-T2.5	32	25.46	24.93	29	21	1
34-T2.5	34	27.06	26.53	32	21	1
36-T2.5	36	28.65	28.12	32	21	1
38-T2.5	38	30.24	29.71	32	21	1
40-T2.5	40	31.83	31.3	34.5	24.5	1
42-T2.5	42	33.42	32.89	37.5	24.5	1
44-T2.5	44	35.01	34.48	40	27	1
46-T2.5	46	36.61	36.08	40	27	1
48-T2.5	48	38.2	37.67	40	27	1
50-T2.5	50	39.79	39.26	44	32	1
60-T2.5	60	47.75	47.22	51	36	1.2