Machine elements

A standard dowel pin is intentionally oversize — a nominal Ø6 dowel measures slightly larger, and the press-fit hole is sized accordingly. This page collects the machine-element numbers that drawings reference but rarely spell out: dowel pin and pin-hole sizes, AS568 O-ring dash sizes with groove width and depth, and the customary shaft and housing fits for rolling bearings.

Each table answers the inspection-side question — what dimension does the callout imply, and what tolerance applies — using the same standards engines the ASdrawn pipeline uses when it reads a drawing.

Nominal Ø (mm)

3 matching dowel rows highlighted.

Dowel pins

Standard	Nominal	Pin tol	Hole tol	Pin max/min	Hole max/min	Unit
iso_2338	1	m6	H7	1.008 / 1.002	1.01 / 1	mm
iso_2338	1.5	m6	H7	1.508 / 1.502	1.51 / 1.5	mm
iso_2338	2	m6	H7	2.008 / 2.002	2.01 / 2	mm
iso_2338	2.5	m6	H7	2.508 / 2.502	2.51 / 2.5	mm
iso_2338	3	m6	H7	3.008 / 3.002	3.01 / 3	mm
iso_2338	4	m6	H7	4.012 / 4.004	4.012 / 4	mm
iso_2338	5	m6	H7	5.012 / 5.004	5.012 / 5	mm
iso_2338	6	m6	H7	6.012 / 6.004	6.012 / 6	mm
iso_2338	8	m6	H7	8.015 / 8.006	8.015 / 8	mm
iso_2338	10	m6	H7	10.015 / 10.006	10.015 / 10	mm
iso_2338	12	m6	H7	12.018 / 12.007	12.018 / 12	mm
iso_2338	16	m6	H7	16.018 / 16.007	16.018 / 16	mm
iso_2338	20	m6	H7	20.021 / 20.008	20.021 / 20	mm
iso_2338	1	h8	H8	1 / 0.986	1.014 / 1	mm
iso_2338	2	h8	H8	2 / 1.986	2.014 / 2	mm
iso_2338	3	h8	H8	3 / 2.986	3.014 / 3	mm
iso_2338	4	h8	H8	4 / 3.982	4.018 / 4	mm
iso_2338	5	h8	H8	5 / 4.982	5.018 / 5	mm
iso_2338	6	h8	H8	6 / 5.982	6.018 / 6	mm
iso_2338	8	h8	H8	8 / 7.978	8.022 / 8	mm
iso_2338	10	h8	H8	10 / 9.978	10.022 / 10	mm
iso_2338	12	h8	H8	12 / 11.973	12.027 / 12	mm
iso_2338	16	h8	H8	16 / 15.973	16.027 / 16	mm
iso_2338	20	h8	H8	20 / 19.967	20.033 / 20	mm
iso_8734	1	m6	H7	1.008 / 1.002	1.01 / 1	mm
iso_8734	2	m6	H7	2.008 / 2.002	2.01 / 2	mm
iso_8734	3	m6	H7	3.008 / 3.002	3.01 / 3	mm
iso_8734	4	m6	H7	4.012 / 4.004	4.012 / 4	mm
iso_8734	5	m6	H7	5.012 / 5.004	5.012 / 5	mm
iso_8734	6	m6	H7	6.012 / 6.004	6.012 / 6	mm
iso_8734	8	m6	H7	8.015 / 8.006	8.015 / 8	mm
iso_8734	10	m6	H7	10.015 / 10.006	10.015 / 10	mm
iso_8734	12	m6	H7	12.018 / 12.007	12.018 / 12	mm
iso_8734	16	m6	H7	16.018 / 16.007	16.018 / 16	mm
iso_8734	20	m6	H7	20.021 / 20.008	20.021 / 20	mm

AS568 dash number

-214 row highlighted.

O-rings

Dash	ID	Cross section	Groove width	Groove depth	Groove tol	Squeeze	Seal	Unit
-006	0.114	0.07	0.104	0.052	0.002	19–32%	face	in
-010	0.239	0.07	0.104	0.052	0.002	19–32%	face	in
-014	0.489	0.07	0.104	0.052	0.002	19–32%	face	in
-020	0.864	0.07	0.104	0.052	0.002	19–32%	face	in
-028	1.364	0.07	0.104	0.052	0.002	19–32%	face	in
-110	0.362	0.103	0.139	0.077	0.003	20–30%	face	in
-210	0.734	0.139	0.182	0.104	0.003	20–30%	face	in
-214	0.984	0.139	0.182	0.104	0.003	20–30%	face	in
-218	1.234	0.139	0.182	0.104	0.003	20–30%	face	in
-222	1.484	0.139	0.182	0.104	0.003	20–30%	face	in
-226	1.984	0.139	0.182	0.104	0.003	20–30%	face	in
-230	2.484	0.139	0.182	0.104	0.003	20–30%	face	in
-325	1.475	0.21	0.28	0.157	0.005	21–30%	face	in
-330	2.1	0.21	0.28	0.157	0.005	21–30%	face	in
-425	4.475	0.275	0.352	0.206	0.005	21–29%	face	in
-430	5.1	0.275	0.352	0.206	0.005	21–29%	face	in

Bearing typeRingLoad

Bearing fits

Bearing type	Ring	Load	Rotating	Shaft tol	Housing tol
Radial Ball	inner	normal	Yes	k5	H7
Radial Ball	inner	normal	No	h6	M7

Why do bearing fits depend on which ring rotates?

The rotating ring needs the interference: a shaft-rotating machine takes a tight shaft fit and a looser housing fit, and the reverse holds for housing rotation. A slipping fit under the rotating load creep-walks the ring and destroys the seat, which is why the recommendation tables key on load case and rotation, not just size. Bearing manufacturers’ catalogs remain the authority for a specific bearing series and load — treat these values as the customary starting point.