Presentation on theme: "Technology Education Dept. Bellwood-Antis High School Mr. Crowell Mr. Mackereth."— Presentation transcript:
Technology Education Dept. Bellwood-Antis High School Mr. Crowell Mr. Mackereth
High Density- Metal is heavy & dense Strength- Metal has strong weight bearing (load) properties Conductive- Will transmit electricity, allows for arc & mig welding. Flexible- Can be bent or shaped easily Versatile-Has many uses & applications
BASE METALS- pure metals (contain no others) & are found on the periodic table. Examples of base metals: SILVERCOPPER GOLD IRONLEAD ALUMINUM ALLOYS- mixtures of 2 or more metals Examples of alloys: STEEL CAST IRON BRASSBRONZE SOLDER
FERROUS METALS- metals that contain IRON (Fe) as one metal in the mixture Examples of ferrous metals: CAST IRON STAINLESS STEEL TOOL ALLOYS NON-FERROUS METALS- any metals (base / alloy) that DO NOT contain IRON Examples of non-ferrous metals: BRASS BRONZEBASE METALS except IRON
LOW CARBON STEEL- mild steel Contains 0.05 to 0.3% carbon (steel is an ALLOY) Soft metal, easy to cut, bend, shape HIGH CARBON STEEL- tool steel Contains 1.5 to 2.5% carbon Very hard metal, doesnt bend, shatters under stress MEDIUM CARBON STEEL- structural beams Contains 0.6 to1.0% carbon Harder than low carbon, but can still be cut & shaped
HOT FINISHED STEEL Steel is formed and allowed to cool in open air. A BLACK FILM forms on the outside of the steel. This film is CARBON that rises to the surface COLD FINISHED STEEL Steel is formed, then cooled in controlled room. NO FILM forms on the outside of the steel. This gives the steel a smooth, reflective surface. COLD FINISHED is 2X to 3X more expensive
SHEET METAL is steel that is pressed by a series of rollers into a flat plate form. Sheet metal is vulnerable to rust, so it can be coated by many different materials. GALVANIZED SHEET METAL coated on all surfaces with a thin layer of ZINC. TIN PLATED SHEET METAL (TIN PLATE) coated on all surfaces with a thin layer of TIN. Coatings keep sheet metals from rusting and becoming weak, also keeps metal attractive
SKETCH- is a ROUGH drawing of a project NO RULER is used in the drawing (FREEHAND) NO DIMENSIONS ARE PLACED ON THE DRAWING PLANS – BLUEPRINTS - DRAWINGS A DETAILED DRAWING of an object or building. Straightedges are used. Dimensions are labeled. PATTERN An object TRACED OUT on top of the metal.
CUTTING STRAIGHT LINES Hand Tools- Straight or Combination Tin Snips Machines- Foot Powered Squaring Shear CUTTING STRAIGHT LINES Hand Tools- Circular Pattern Tin Snips Machines- Table Shear or Punches BENDING / SHAPING SHEET METAL BY HAND using a block of wood or table stake ROLLING MACHINE- makes a cylindrical shape BOX & PAN BRAKE-makes accurate, straight bends
First, a pair of PARALLEL lines are drawn on the metal. Then metal is folded, rolled, or cut on these lines PARALELL LINE is used to make PRISMS & CYLINDERS.
First, a fixed point is established on the metal (can be centered or on edge) If lines are drawn out & away from the center, then RADIAL LINE can make: PYRAMIDS If an arc or radius is drawn around the point, then RADIAL LINE can make: CYLINDERS
(1) One set of parallel lines are drawn (2) A second set of parallel lines are drawn at 90 degrees (perpendicular) to the first set of lines (3) metal is folded or cut on these lines It is used to make BOXES & TRAYS. Your shop project was made using this method.
SOLDERING is a process used to seal the seams/joints with solder & a heat source. A SOLDERING IRON heats the solder alloy. Soldering metal acts GLUE does on wood pieces FLUX is applied to the metal to make solder travel into the seams (prevents surface tension.) Solder is a mixture (alloy) of LEAD and TIN. SPECIAL NOTE: Copper water pipes need to be soldered with LEAD FREE SOLDER to prevent lead from dissolving into water (lead poisoning.)
PROPANE TORCH Used for copper water pipes & other projects NOT USED for sheet metal (discolors & burns.) SOLDERING COPPER & OPEN FLAME Used decades ago by students and industry Open fires/forges were viewed as DANGEROUS. ELECTRIC SOLDERING IRON Uses electricity to heat the copper coated iron. Safe enough to be used in schools. You will be using an electric soldering iron for your projects.
SOLDERING IRONS are cleaned using a SAL-AMONIAC BLOCK or WIRE BRUSH. This process removes the oxidized LEAD (a black powdered residue) from the iron TIN is left on the soldering iron. This process is known as TINNING COPPER Because lead is poisonous, WASH YOUR HANDS THOUROUGHLY when finished.