Home > Gaskets > Full Face Gaskets > Teadit 24SH Full Face Gasket

Teadit 24SH 100% Expanded PTFE Full Face Gasket

Choose Favorites List

Zoom In Zoom Out Enlarge

Teadit 24SH Full Face Gasket

Full Face gaskets are a flat sealing element, consisting of an inner and outer diameter, and a specified number of bolt holes, the center of which are evenly spaced around a bolt circle. Full face gaskets are designed to fill the entire space between flat-faced flanges, with bolt holes that match the size and arrangement of the bolt holes in the intended flanges. ASME B16.21 and ASME B16.47 govern the dimensions of full face gaskets for standard and large diameter pipe flanges. TEADIT 24SH is a large gasket sheet produced from 100% pure, multi-directionally expanded PTFE. Universally employable gasket sheet for all applications. It is suitable for all types of flanges, nearly all media, a wide temperature range and for applications with the toughest demands on purity. It is inherently clean and non-toxic. Gaskets of multi-directionally expanded PTFE have exceptional mechanical strength which allows operation with minimal creep at elevated temperatures. The excellent malleability of TEADIT 24SH makes repairing small damage and/or irregularities of the sealing area (flange surface) unnecessary. Gaskets cut from TEADIT 24SH are dimensionally stable, i. e. they do not get wider when compressed. This allows narrow flange faces to be sealed safely. TEADIT 24SH is quick and simple to install. The used gasket can be removed easily and without residue.

Products
Governing Standards
Service Limits
Physical Properties
Dimensional Specifications

Dimensional Specifications

Dimensional SpecificationsTeadit 24SH Full Face Gasket

Per ASME B16.21-2016
		Pipe Diameter
		1/2	3/4	1	1 1/4	1 1/2	2	2 1/2	3	3 1/2	4	5	6	8	10	12	14	16	18	20	24
Inside Diameter		0.84	1.06	1.31	1.66	1.91	2.38	2.88	3.50	4.00	4.50	5.56	6.62	8.62	10.75	12.75	14.00	16.00	18.00	20.00	24.00
Outside Diameter per Class	150#	3.50	3.88	4.25	4.63	5.00	6.00	7.00	7.50	8.50	9.00	10.00	11.00	13.50	16.00	19.00	21.00	23.50	25.00	27.50	32.00
	300#	3.75	4.62	4.88	5.25	6.12	6.50	7.50	8.25	9.00	10.00	11.00	12.50	15.00	17.50	20.50	23.00	25.50	28.00	30.50	36.00
	600#	3.75	4.62	4.88	5.25	6.12	6.50	7.50	8.25	9.00	10.75	13.00	14.00	16.50	20.00	22.00	23.75	27.00	29.25	32.00	37.00
Bolt Circle Diameter per Class	150#	2.38	2.75	3.13	3.50	3.88	4.75	5.50	6.00	7.00	7.50	8.50	9.50	11.75	14.25	17.00	18.75	21.25	22.75	25.00	29.50
	300#	2.62	3.25	3.50	3.88	4.50	5.00	5.88	6.62	7.25	7.88	9.25	10.62	13.00	15.25	17.75	20.25	22.50	24.75	27.00	32.00
	600#	2.62	3.25	3.50	3.88	4.50	5.00	5.88	6.62	7.25	8.50	10.50	11.50	13.75	17.00	19.25	20.75	23.75	25.75	28.50	33.00
Number of Bolt Holes per Class	150#	4	4	4	4	4	4	4	4	8	8	8	8	8	12	12	12	16	16	20	20
	300#	4	4	4	4	4	8	8	8	8	8	8	12	12	16	16	20	20	24	24	24
	600#	4	4	4	4	4	8	8	8	8	8	8	12	12	16	20	20	20	20	24	24
Bolt Hole Diameter per Class	150#	0.63	0.63	0.63	0.63	0.63	0.75	0.75	0.75	0.75	0.75	0.88	0.88	0.88	1.00	1.00	1.13	1.13	1.25	1.25	1.38
	300#	0.63	0.75	0.75	0.75	0.88	0.75	0.88	0.88	0.88	0.88	0.88	0.88	1.00	1.12	1.25	1.25	1.38	1.38	1.38	1.62
	600#	0.63	0.75	0.75	0.75	0.88	0.75	0.88	0.88	1.00	1.00	1.12	1.12	1.25	1.38	1.38	1.50	1.62	1.75	1.75	2.00

Per ASME B16.47-2017
Series A		Pipe Diameter
Series A		26	28	30	32	34	36	38	40	42	44	46	48	50	52	54	56	58	60
Inside Diameter		26.00	28.00	30.00	32.00	34.00	36.00	38.00	40.00	42.00	44.00	46.00	48.00	50.00	52.00	54.00	56.00	58.00	60.00
Outside Diameter per Class	150#	34.25	36.50	38.75	41.75	43.75	46.00	48.75	50.75	53.00	55.25	57.25	59.50	61.75	64.00	66.25	68.75	71.00	73.00
	300#	38.25	40.75	43.00	45.25	47.50	50.00	46.00	48.75	50.75	53.25	55.75	57.75	60.25	62.25	65.25	67.25	69.25	71.25
	600#	40.00	42.25	44.50	47.00	49.00	51.75	50.00	52.00	55.25	57.25	59.50	62.75	65.75	67.75	70.00	73.00	75.00	78.50
Bolt Circle Diameter per Class	150#	31.75	34.00	36.00	38.50	40.50	42.75	45.25	47.25	49.50	51.75	53.75	56.00	58.25	60.50	62.75	65.00	67.25	69.25
	300#	34.50	37.00	39.25	41.50	43.50	46.00	43.00	45.50	47.50	49.75	52.00	54.00	56.25	58.25	61.00	63.00	65.00	67.00
	600#	36.00	38.00	40.25	42.50	44.50	47.00	45.75	47.75	50.50	52.50	54.75	57.50	60.00	62.00	64.25	66.75	68.75	71.75
Number of Bolt Holes per Class	150#	24	28	28	28	32	32	32	36	36	40	40	44	44	44	44	48	48	52
	300#	28	28	28	28	28	32	32	32	32	32	28	32	32	32	28	28	32	32
	600#	28	28	28	28	28	28	28	32	28	32	32	32	28	32	32	32	32	28
Bolt Hole Diameter per Class	150#	1.38	1.38	1.38	1.63	1.63	1.63	1.63	1.63	1.63	1.63	1.63	1.63	1.88	1.88	1.88	1.88	1.88	1.88
	300#	1.75	1.75	1.88	2.00	2.00	2.12	1.62	1.75	1.75	1.88	2.00	2.00	2.12	2.12	2.38	2.38	2.38	2.38
	600#	2.00	2.12	2.12	2.38	2.38	2.62	2.38	2.38	2.62	2.62	2.62	2.88	3.12	3.12	3.12	3.38	3.38	3.62
Per ASME B16.47-2017
Series B		Pipe Diameter
Series B		26	28	30	32	34	36	38	40	42	44	46	48	50	52	54	56	58	60
Inside Diameter		26.00	28.00	30.00	32.00	34.00	36.00	38.00	40.00	42.00	44.00	46.00	48.00	50.00	52.00	54.00	56.00	58.00	60.00
Outside Diameter per Class	150#	30.94	32.94	34.94	37.06	39.56	41.62	44.25	46.25	48.25	50.25	52.81	54.81	56.81	58.81	61.00	63.00	65.94	67.94
	300#	34.12	36.25	39.00	41.50	43.62	46.12	48.12	50.12	52.50	54.50	57.50	59.50	61.50	63.50	65.88	69.50	71.94	73.94
	600#	35.00	37.50	40.25	42.75	45.75	47.75
Bolt Circle Diameter per Class	150#	29.31	31.31	33.31	35.44	37.69	39.75	42.12	44.12	46.12	48.12	50.56	52.56	54.56	56.56	58.75	60.75	63.44	65.44
	300#	31.62	33.75	36.25	38.50	40.62	42.88	44.88	46.88	49.00	51.00	53.75	55.75	57.75	59.75	62.12	65.00	67.44	69.44
	600#	31.75	34.00	36.50	38.75	41.50	43.50
Number of Bolt Holes per Class	150#	36	40	44	48	40	44	40	44	48	52	40	44	48	52	56	60	48	52
	300#	32	36	36	32	36	32	36	40	36	40	36	40	44	48	48	36	40	40
	600#	28	28	28	28	24	28
Bolt Hole Diameter per Class	150#	0.88	0.88	0.88	0.88	1.00	1.00	1.12	1.12	1.12	1.12	1.25	1.25	1.25	1.25	1.25	1.25	1.38	1.38
	300#	1.38	1.38	1.50	1.62	1.62	1.75	1.75	1.75	1.88	1.88	2.00	2.00	2.00	2.00	2.00	2.38	2.38	2.38
	600#	1.75	1.88	2.00	2.12	2.38	2.38

All dimensions are in inches.

Teadit 24SH Full Face Gasket

of 1

Sort By

Show

View

Pipe Diameter Flange Rating Series Thickness Item # Availability Price Quantity UOM

1/2

150#

1/8

GFQSH-1500050-1/8

1-3 Working Days

$26.34366/EA

See Quantity Discounts

1/2 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$26.34366/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$26.34366/ EA
280	$24.58654/ EA
1120	$18.00326/ EA
3360	$12.99796/ EA

1/2

300#, 400#, 600#

1/8

GFQSH-3460050-1/8

1-3 Working Days

$30.24145/EA

See Quantity Discounts

1/2 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$30.24145/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$30.24145/ EA
240	$28.22434/ EA
960	$20.66701/ EA
2880	$14.92113/ EA

3/4

150#

1/8

GFQSH-1500075-1/8

1-3 Working Days

$32.29115/EA

See Quantity Discounts

3/4 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$32.29115/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$32.29115/ EA
230	$30.13733/ EA
920	$22.06777/ EA
2760	$15.93245/ EA

3/4

300#, 400#, 600#

1/8

GFQSH-3460075-1/8

1-3 Working Days

$46.0006/EA

See Quantity Discounts

3/4 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$46.0006/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$46.0006/ EA
160	$42.93236/ EA
640	$31.43681/ EA
1920	$22.6967/ EA

150#

1/8

GFQSH-1500100-1/8

1-3 Working Days

$38.84346/EA

See Quantity Discounts

1 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$38.84346/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$38.84346/ EA
200	$36.2526/ EA
800	$26.54562/ EA
2400	$19.16536/ EA

300#, 400#, 600#

1/8

GFQSH-3460100-1/8

1-3 Working Days

$51.10805/EA

See Quantity Discounts

1 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$51.10805/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$51.10805/ EA
150	$47.69914/ EA
600	$34.92724/ EA
1800	$25.21671/ EA

1 1/4

150#

1/8

GFQSH-1500125-1/8

1-3 Working Days

$46.0006/EA

See Quantity Discounts

1 1/4 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$46.0006/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$46.0006/ EA
170	$42.93236/ EA
680	$31.43681/ EA
2040	$22.6967/ EA

1 1/4

300#, 400#, 600#

1/8

GFQSH-3460125-1/8

1-3 Working Days

$59.27324/EA

See Quantity Discounts

1 1/4 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$59.27324/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$59.27324/ EA
130	$55.31971/ EA
520	$40.50733/ EA
1560	$29.24542/ EA

1 1/2

150#

1/8

GFQSH-1500150-1/8

1-3 Working Days

$53.76257/EA

See Quantity Discounts

1 1/2 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$53.76257/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$53.76257/ EA
150	$50.17661/ EA
600	$36.74134/ EA
1800	$26.52645/ EA

1 1/2

300#, 400#, 600#

1/8

GFQSH-3460150-1/8

1-3 Working Days

$80.67746/EA

See Quantity Discounts

1 1/2 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$80.67746/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$80.67746/ EA
100	$75.29627/ EA
400	$55.13498/ EA
1200	$39.80626/ EA

150#

1/8

GFQSH-1500200-1/8

1-3 Working Days

$77.41811/EA

See Quantity Discounts

2 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$77.41811/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$77.41811/ EA
110	$72.25432/ EA
440	$52.90753/ EA
1320	$38.19809/ EA

300#, 400#, 600#

1/8

GFQSH-3460200-1/8

1-3 Working Days

$90.85875/EA

See Quantity Discounts

2 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$90.85875/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$90.85875/ EA
90	$84.79847/ EA
360	$62.09287/ EA
1080	$44.82971/ EA

2 1/2

150#

1/8

GFQSH-1500250-1/8

1-3 Working Days

$105.37464/EA

See Quantity Discounts

2 1/2 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$105.37464/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$105.37464/ EA
80	$98.34615/ EA
320	$72.01303/ EA
960	$51.99185/ EA

150#

1/8

GFQSH-1500300-1/8

1-3 Working Days

$94.62213/EA

See Quantity Discounts

3 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$94.62213/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$94.62213/ EA
80	$88.31083/ EA
320	$64.66476/ EA
960	$46.68656/ EA

300#, 400#, 600#

1/8

GFQSH-3460300-1/8

1-3 Working Days

$120.02494/EA

See Quantity Discounts

3 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$120.02494/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$120.02494/ EA
60	$112.01928/ EA
240	$82.02505/ EA
720	$59.22031/ EA

150#

1/8

GFQSH-1500400-1/8

1-3 Working Days

$130.64305/EA

See Quantity Discounts

4 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$130.64305/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$130.64305/ EA
60	$121.92916/ EA
240	$89.28146/ EA
720	$64.45928/ EA

150#

1/8

GFQSH-1500500-1/8

1-3 Working Days

$148.51071/EA

See Quantity Discounts

5 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$148.51071/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$148.51071/ EA
50	$138.60504/ EA
200	$101.49222/ EA
600	$73.27518/ EA

150#

1/8

GFQSH-1500600-1/8

1-3 Working Days

$165.82394/EA

See Quantity Discounts

6 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$165.82394/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$165.82394/ EA
50	$154.76348/ EA
200	$113.32408/ EA
600	$81.81753/ EA

150#

1/8

GFQSH-1500800-1/8

1-3 Working Days

$231.9519/EA

See Quantity Discounts

8 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$231.9519/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$231.9519/ EA
30	$216.48071/ EA
120	$158.51593/ EA
360	$114.44507/ EA

150#

1/8

GFQSH-1501000-1/8

1-3 Working Days

$302.01126/EA

See Quantity Discounts

10 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$302.01126/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$302.01126/ EA
25	$281.8671/ EA
100	$206.39449/ EA
300	$149.01235/ EA

150#

1/8

GFQSH-1501200-1/8

1-3 Working Days

$426.74042/EA

See Quantity Discounts

12 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$426.74042/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$426.74042/ EA
25	$398.27684/ EA
100	$291.63441/ EA
300	$210.55373/ EA

300#

1/8

GFQSH-3001400-1/8

1-3 Working Days

$716.11748/EA

See Quantity Discounts

14 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$716.11748/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$716.11748/ EA
40	$668.35244/ EA
160	$489.39468/ EA
480	$353.33236/ EA

300#

1/8

GFQSH-3001600-1/8

1-3 Working Days

$847.83578/EA

See Quantity Discounts

16 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$847.83578/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$847.83578/ EA
40	$791.28513/ EA
160	$579.41097/ EA
480	$418.32217/ EA

300#

1/8

GFQSH-3001800-1/8

1-3 Working Days

$989.23135/EA

See Quantity Discounts

18 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$989.23135/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$989.23135/ EA
30	$923.24962/ EA
120	$676.0407/ EA
360	$488.08675/ EA

300#

1/8

GFQSH-3002000-1/8

1-3 Working Days

$1,140.30418/EA

See Quantity Discounts

20 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$1,140.30418/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$1140.30418/ EA
30	$1064.24589/ EA
120	$779.28388/ EA
360	$562.62608/ EA

300#

1/8

GFQSH-3002400-1/8

1-3 Working Days

$1,548.36211/EA

See Quantity Discounts

24 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

$1,548.36211/EA

Qty

1-3 Working Days

Product Detail

Quantity	Price
Quantity	Price
1	$1548.36211/ EA
20	$1445.08636/ EA
80	$1058.15067/ EA
240	$763.96186/ EA

Temperature	Minimum: -450F (-268C)
	Maximum Service: 500F (260C)
	Short Term Max: 600F (315C)
Pressure	Vacuum up to: 2900 psi (200 bar)
pH	0-14*
Density	0.9 g/cm^3

Typical Physical Properties:
Color			White
Compressibility - ASTM F36M			45%
Recovery - ASTM F36M			14%
Tensile Strength Across Grain - ASTM F152			>20 MPa
Stress Retention - DIN 52913			15 MPa
Specific Leakage Rate L - VDI 2440 / TA LUFT			2.6E^(-7)

Teadit 24SH Full Face Gasket

Technical Data

Governing Standards

Governing StandardsTeadit 24SH Full Face Gasket

Service Limits

Service LimitsTeadit 24SH Full Face Gasket

Physical Properties

Physical PropertiesTeadit 24SH Full Face Gasket

Dimensional Specifications

Dimensional SpecificationsTeadit 24SH Full Face Gasket

Pipe Diameter

Flange Rating

Outside Diameter

Inside Diameter

1/2 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

1/2 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

3/4 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

3/4 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

1 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

1 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

1 1/4 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

1 1/4 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

1 1/2 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

1 1/2 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

2 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

2 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

2 1/2 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

3 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

3 300#/400#/600# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

4 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

5 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

6 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

8 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

10 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

12 150# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

14 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

16 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

18 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

20 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

24 300# 1/8 TEADIT 24SH EXPANDED PTFE FULL FACE GASKET

ASME B16.21	Covers types, sizes, materials, dimensions, tolerances, and markings for nonmetallic flat gaskets.
ASME B16.47	Covers pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing for pipe flanges in sizes NPS 26 through NPS 60. Included are flanges with rating class designations 75, 150, 300, 400, 600, and 900 with requirements given in both SI (Metric) and U. S. Customary units, with diameter of bolts and flange bolt hole expressed in inch units.