0101-0137123

(Last Revised 11/10/06)

AR

AR

MS

MS

MS

AZ

AZ

LA

LA

DE

DE

Aztec

Manufacturing

Partnership, Ltd.

75-2403896

12/4/91

TX

TX

Rig-A-Lite

Partnership,

Ltd.

75-0353821

12/4/91

TX

TX

TX

TX

Aztec

Manufacturing-

Waskom

Partnership,

Ltd.

75-2403909

12/4/91

International

Galvanizers

Partnership, Ltd.

76-0553184

11/26/97

TX

TX

1% General

Partner

99% Limited

Partner

MS

Stateof

Commercial

Domicile

Date of Formation

Reporting Legend:

Domestic

Corporation

Domestic

Limited

Partnership

State of Formation

TX

DE

Footnote Reference

FEIN

MS

Drilling Rig

Electrical Systems

Co.

Partnership, Ltd.

75-2733744

12/29/97

TX

TX

TX

TX

AL

AL

TX

DE

Arbor-Crowley, Inc.

51-0337454

12/3/91

KS

KS

Atkinson Industries,

Inc.

48-0126010

1/23/36

Aztec Industries,

Inc.

75-1318815

8/21/69

MS

MS

MS

TX

DE

TX

DE

Domestic “Check-

the-Box”Limited

Partnership

Domestic

LLC

MA

DE

LA

DE

TX

DE

1% General

Partner

99% Limited Partner

Exhibit 21 –

Subsidiaries of Registrant

Gulf Coast

Galvanizing, Inc.

75-2493283

1/28/94

The Calvert Company,

Inc.

64-0792921

9/28/90

Arkgalv, Inc.

( d/b/a Arkansas

Galvanizing, Inc.)

75-2254883

11/29/88

AZZ incorporated

75-0948250

3/26/56

AZZ GP, LLC

No FEÍN

9/30/2000

AZZ LP, LLC

No FEÍN

9/30/2000

AZZ

Group, LP

75-2403898

9/30/00

Aztec Industries, Inc. -

Moss Point

75-2107319

3/1/86

Automatic

Processing

Incorporated

64-0594499

1/6/77

AZZ

75-2222222

3/29/59

AZZ Holdings, Inc.

51-0337457

12/3/91

Arizona Galvanizing,

Inc.

75-2508628

4/28/93

Hobson Galvanizing,

Inc.

72-1350019

4/4/97

CGIT Systems, Inc.

75-2832437

9/1/99

Westside Galvanizing

Services, Inc.

72-0866859

2/1/2000

Central Electric

Company

MO

43-0995652     

MO

Carter and Crawley, Inc.

SC

75-2960819      

DE

Central

Electric

Manufacturing

Company

MO

43-0716500

MO

Electrical

Power Systems,

Inc.

OK

43-1759385

MO

Clark Control

Systems, Inc.

TN

63-1148768

MO

Witt Galvanizing

Cincinnati, Inc.

OH

20-5044366

DE

Witt Galvanizing

Muncie, Inc.

IN

20-5044420

DE

Witt Galvanizing

Plymouth, Inc.

IN

20-5044257

DE