Crack a Valve 
Small valve opening to permit flow through. 

Cracking 
1. The breaking down of heavier hydrocarbons by heat and pressure or by catalysts into lighter hydrocarbons of lower molecular weight, for example gasoline from petroleum. 
2. Paint defect brought about by improper material mixtures. 

Crackle Lacquer 
Paint Used where a smooth surface is not desired, this paint develops an alligator skin texture once it is sprayed over a gloss base lacquer. 

Cradling 
Support framework for lath and plaster on a vaulted ceiling. 

Craft 
Skill requiring manual ability. 

Craftsman 
Person who is skilled at a craft, which requires manual ability. 

Craftsman Style 
Architectural style, which evolved, near the turn of the century, as part of the Arts and Crafts movement. 

Cramp 
Iron or steel rod, which holds blocks of stone together by having ends, bent at right angles to the length of the rod. 

Crane 
Any one of the various motorized, machines for lifting or moving heavy weights by use of a horizontal bean or movable projecting arm traveling on an overhead support. They are used on construction sites for many jobs. 

Crane Bridge 
The overhead structural support spanning the distance between the girders or the rails on the bridge crane. Crane Cab Seating area, attached to the bridge or trolley, for the operator of the crane. 

Crane Girders 
Also called crane rails, this structural section supports the bridge crane. 

Crane Rails 
Also called crane girders, this structural section supports the bridge crane. 

Crane Jib 
Different types of jibs, which are the extensions that top a crane tower, making additional moving and lifting possible. The Saddle Jib, which is a horizontal extension positioned at a right angle to the tower has a hook attached to a trolley which moves along the length of the jib which changes the hook reach. Saddle jibs can be used for both distance and close loads. Greater lifting height can be obtained from the use of a luffing jib, which is a pivoting extension at the top of the tower, with a hook suspended from its end, which can be changed from close to vertical to close to horizontal. Fixed Luff jibs are permanently at a horizontal angle but can pivot at the tip of the tower. Its hook can be fixed to a trolley so it can either move along the length of the jib or suspend from the end of the jib. 

Crane, Manual 
Crane, which is not machine-powered and is operated by hand with a closed-loop chain, working like a pulley. 

Crane Rail 
The structure on which the ends of a gantry or bridge crane ride. 

Crane, Remote 
Crane that is radio-controlled. 

Craning 
Use as a lifting device, of a backhoe bucket, with a cable or chain wrapped around the bucket teeth. 

Crank 
Mechanism, which converts between rotary and reciprocating motion with use of a lever, which has one end, attached to the outside diameter of a wheel, which goes around with the wheel when it is turned. A crank connected to a piston within a cylinder is attached to the other end of the lever. The motion of the crank end of the lever is changed into a reciprocating or sliding motion as the lever moves along with the wheel. 

Crankcase 
Crankshaft enclosure in a machine. 

Crankpin
Pin, which attaches the connecting rod at the outer periphery of the crank. 

Crankshaft 
Used in both machinery and piston engines, this rotating shaft with connecting rods attached, for converting between rotary and reciprocating motion. 

Crank Shaper 
Metal shaper with a crank pin on the main driving gear to drive the to drive the reciprocating arm. 

Crater 
A hole-like defect. 

Crawl Space 
Space between the ground and the first floor of a home, to allow for access to wiring, plumbing, etc., approximately four feet. 

Crawl Space Plenum 
Heating system that works by accumulating heated air in the crawl space and by using fans to distribute the heated air. 

Crawling 
Uneven texture of a paint surface, which can be caused by shrinkage while drying. 

Crazing 
Also referred to as stress cracking, fine cracking which appears in the surface of paint, porcelain, etc. 

CRB 
see Certified Residential Broker. 

Creative Financing 
Innovative financing arrangements to help sell a property. 

Credit 
Money a lender extends to a borrower who gives a commitment to repay the loan within a certain amount of time. 

Credit Application 
Form used to record information about an applicant seeking a loan. 

Credit History 
The record of a person's current and past debt payments. 

Credit Life Insurance 
Insurance, which pays off a mortgage in the event of the borrower's death. 

Credit Limit 
Maximum amount of money that can be loaned to a prospective borrower. 

Credit Rating 
Degree of creditworthiness assigned to a person based on credit history and financial status. 

Credit Report 
Detailed account of an individual's credit, employment and residence history used by a lender to determine a loan applicant's creditworthiness. The three largest credit bureaus are Trans Union Corp., Equifax and Experian (formerly TRW). 

Credit Repository 
Large companies that gather financial and credit information from various sources about individuals who have applied for credit. 

Credit Union 
Nonprofit cooperative organization providing banking and financial services such as home improvement loans, home equity loans and mortgages to its members. 

Creditor 
A person or institution to whom a debt is owed. 

Creep 
To change in shape metals, materials, etc. as the result of stress, temperature, etc. 

Creeper 
Low platform with wheels that is used for a person to lie on and slide under a machine or automobile. 

Creeping
Paint that runs together in small drops. 

Creep Speed 
Slow but constant movement speed. 

Crenels 
These square notches, which are evenly spaced at the top edge of a wall, are also called crenellations. 

Crenellations 
These square notches, which are evenly spaced at the top edge of a wall, are also called crenels. 

Creosote
Coal tar based chemical preservative used to treat wood items to protect them from decal and deterioration. 

Crescent Wrench 
Trade name of an open-ended wrench with jaws, which adjust so that only one wrench is needed to fit a large number of fastener head of different sizes. 

Crest 
The peak of a ridge. 

Crib 
1. Framework of wooden or metal bars for support or strengthening, as in a mine. 
2. Barrier that reduces the rate of flow in a river and also contains and stores floating logs. 
3. Small dwelling or room or space. 
4. Grain storage bin. 

Cribbing 
1. Placement of wood to keep a load from moving during transit. 
2. Framework of timber lining and supporting a mineshaft. 
3. Trenching a narrow area with a backhoe in a way so as to allow the areas on either side of the trench to remain untouched. The soil is placed in the trench close to the machine and removed as the trenching progresses. 

Cricket 
Peaked structure, which diverts water at the juncture of a roof slope and a chimney or two roof slopes. 

Crimp 
1. Mechanical clinching of sheet metal pieces for fastening purposes or to make material less flexible. 
2. To evenly fold into corrugations. 
3. Fold sheet metal for seams. 

Crimping Tool 
1. Tool shaped like a pair of pliers, which is used to make corrugations in the end of a sheet metal duct to reduce its size. 
2. Tool that is used to squeeze an electrical connector tightly around a conductor. 
3. Tool used to clinch metal studs or corner beads in place without additional separate fasteners. 

Cripple 
Short stud used, in wall framing, between a top plate and a header or a sill and a sole plate. 

Critical Path Method (CPM) 
Work scheduling where all major jobs are laid out in a diagram to show the proper sequence of work and the necessary time required for each, providing a visualization so that indications can be made to show which operations are critical to others. 

Critical Point 
The stage in temperature and pressure at which the liquid and vapor phases of a substance are equal. 

Critical Pressure 
The minimum pressure needed to liquefy a gas at its critical temperature.